Master Thesis DMD Tongji University - Flood community resilience

硕士学位论文

建成环境对社区洪涝韧性的影响研究

——以法兰西岛大区为例

学 号：2093158

所在院系：建筑与城市规划学院

学科门类：工学

学科专业：城乡规划学

指导教师： Gan Jing 干靓

Adissertation submitted to Tongji University in conformity with the requirements for the degree of Engineering

THE INFLUENCE OF BUILT ENVIRONMENT ON COMMUNITY FLOOD RESILIENCE -CASE STUDY OF ILE-DEFRANCE REGION

Candidate: Gwendoline Charreau

Student Number: 2093158

School/Department: College ofArchitecture and Urban Planning

Discipline: Engineering

Major: Town and Country Planning

Supervisor: Gan Jing

December, 2022

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ACKNOWLEDGEMENTS

I'm grateful to Tongji University for the opportunity to study in an impressive international and intellectual environment. Inspired by Chinese and French guidance, this master thesis is the result of a genuine passion for town planning.

Thank to my supervisor Gan Jing 干靓 with her precise vision this research only grew stronger. Her commitment to this master thesis pushed the boundaries of my knowledge. Having spent precious time with her on this study has given me the greatest pleasure

It was with my teachers, throughout my studies at Tongji, that I developed an increased vision on town planning. Many thanks for your expertise and help on all the maps, methodology and hard work done.

To Emilie Gascon, Doctor of Architecture and professor at ENSA-Versailles, who allowed me to become interested in the subject of water and resilience. It is thanks to the enthusiasm of people like Emilie that the passion for research is passed on to the younger generation and still holds strong.

Many thanks to Ingrid Taillandier. During our exchanges, I learned through her strength of character that in research, as in life, one must dare. Her enthusiasm for the Franco-Chinese masters is an example in the field of research to develop strong and innovative partnerships.

Thank you to all of those who can recognize themselves, and allowed me to learn as much as they did through this master thesis. Without your personal resilience, there is no discovery.

ABSTRACT

Water is an indispensable resource for human and economic activities, it participates in structuring the landscape; it constitutes an ecosystem, it used to shape our environment, etc. But water also is, and always was, a risk factor, especially with the flood risk. Civilization was built around water because it is a vital asset to life despite flood. Nowadays, water damages are among the most damaging natural hazard and are likely to become more frequent, more relevant, and more damaging in the future due to the effects of the increasing population and the impact of climate change. In the long term, the goal for many flood protection systems seems to be linked to resilience. The general point of view is to support city planning renewal projects to create flood resilient communities. Therefore, it can be wonder :

How the influence of the built environment can improve communities to be more flood resilient?

The purpose of this master thesis is consequently to research among the existing built environments of communities the influence for a better flood resilience.

The methodology will be divided in four parts. The literature review, to provide an overview of current knowledge on flood; a mapping analysis to visualization through maps and plans the flood risk context in Ile-de-France Region; An on-site survey to investigate the built environment data of the selected cases and finally the questionnaire withsemi-structureinterviewtoexplorelocal residents’pointofviews and experiences. The results will shows how the resilient built environment influence can be divided into three important factors. Each of those factors influences the vulnerability and therefore the resilience of the built environment and their community. The built environment basic resilience, its mobility / evacuation system and the main risk culture it needs to impact the communities. As a whole, this master thesis try to demonstrate why the addition of resilience in the flood risk management expanded the traditional way to approach it. Furthermore, it can also promotes strong recovery systems and addresses many factors that contribute to good living conditions in flood areas.

Key words : Flood, Resilience, Vulnerability, Built environment, Communities

水是人类和经济活动不可或缺的资源，它参与景观的构建，构 成生态系统，也曾塑造我们的环境。然而水同时也一直是一个风险 因素，尤其是在洪水风险方面。文明是围绕着水而建立的，因为水 是生命的重要资产，尽管洪水泛滥。如今，水灾害是最具破坏性的 自然灾害之一，由于人口增长和气候变化的影响，水灾害在未来可 能会变得更频繁、更具相关性和更具破坏性。从长远来看，许多防 洪系统的目标似乎与韧性有关。关于这一议题的观点整体上支持创 建韧性社区的城市规划更新项目。因此，提出了以下令人好奇的研 究问题：

建成环境的影响如何提高社区的洪涝韧性？

由此，本论文的目的在于研究社区现有建筑环境对更好的洪涝 韧性的影响。

研究分为四个部分。一、通过文献综述概述当前有关洪涝灾害 的认知；二、对法兰西岛大区洪涝风险背景进行可视化地图分析； 三、通过现场调查所选案例社区的建成环境数据和半结构式访谈问 卷，探讨当地居民的观点和经验。研究结果表明，韧性建成环境的 影响可分为三个重要因素。每个因素都会影响建成环境及其社区的 脆弱性，从而影响其韧性。建成环境基本韧性、其移动性/疏散系统

以及所需的主要风险文化将影响社区。总体而言，本论文试图说明 为什么在洪水风险管理中增加韧性扩展了传统的方法。此外，它还 可以促进强大的恢复系统，并解决许多有助于洪水地区良好生活条 件的因素。

关键词：洪水、韧性、脆弱性、建成环境、社区

1.5 Methodology

1.1 Problem statement

1.1.1 Introduction

1.1.2 Key factors

1.1.3 Communities flood danger

1.1.4 Flood hard or soft adaptation : Resistance or Resilience

1.2 Research question

1.3 Aims and significance

1.4 Key words & Definitions

1. INTRODUCTION

1.1 Problem statement

“Eventually, all things merge into one, and a river runs through it. The river was cut by the world's great flood and runs over rocks from the basement of time. On some of the rocks are timeless raindrops. Under the rocks are the words, and some of the words are theirs. I am haunted by waters.”

1.1.1 Introduction

In our contemporary society, water damage, and therefore floods, are among the most frequent and harmful natural hazards 1 (see Fig.1). They are likely to become more frequent, relevant, and damaging in the future (see Fig.2) due to the increasing population and the impact of climate change (see Fig.2). Therefore, adaptation to the consequences of global warming and overpopulation seems vital. The impacts of the industrial past century are world wild. The current impacts and future risks associated with extreme natural events demand resilient solutions for climate change adaptation and disaster risk reduction. Especially the one link to water damage. It is precisely these issues that make town planning and the provision of infrastructure so difficult but necessary for the future. Faced with global warming, our built environment is on the front line.

Cities’ future are unlikely to prosper without planning with flood, especially for the most endangered communities.

1 UNDRR Report, Global Assessment Report on Disaster Risk Reduction, Geneva, Switzerland, United Nations Office for Disaster Risk Reduction (UNDRR), 2019

Norman Maclean, A River Runs Through it - 1976

1.1.1 Fig.1 : Percentage of occurrences of natural disasters by disaster type (19952015) - In the report of “The Human Cost of Weather Related Disasters” by the Centre for Research on the Epidemiology of Disasters – 2017

1.1.1 Fig.2 : Change in proportion of population exposed to floods – BBC, Data from : Global flood data base 2018 - 2021

1.1.2 Key Factors

Floods always happened, but the frequency of them increases and drives up the danger plus the bill for inhabitants, governments, and insurers. Flood affects nearly a third of the world's population, more than any other natural or man-made disaster 2 (see Fig.3). Over 5,000 lives are lost to flooding each year.3 75% of people dying during a flood are drowning 4 .

Flooding causes over 40 billion dollars in damages worldwide each year. In 2021, it cost 82 billion dollars for the built environment and urban area. As an example, the floods in Germany and neighbouring countries in Europe in July 2021 alone, resulted in more than 40 billion dollars in economic losses, of which only 13 billion dollars was covered by insurance. Deficiencies in flood protection are particularly relevant worldwide, with only 34% covered in Europe, and only 7% of economic losses covered by insurance in Asia 5 Which is a lacking risk management element knowing that the most destructive weather-related disaster from 1995 to 2015 happened in North America and East Asia (see Fig.4). In the China River Valley alone, some of the worst floods in the world havekilled millions of people 6 . In Europe the country with the most floods from 1995 to 2015is France (see Fig.4).As a matter of fact, the number of floods globally has increased in thepast six decades across theglobe (see Fig.5)andwill likely increase in the future (see Fig.2).

With those new risks/vulnerabilities, and despite existing risk management strategies, communities face increasing difficulties to stay safe.

The particularity of flood is that there is a different type of them, but they are all defined as an overflow of water that submerges usually dry land. The different types of floods can be divided into 6 : River flood ; Coastal flood; Reservoir flood; Sewer flood ; Groundwater flood; and Surface waterflood, due mostly because of rainfall.

2 WHO (World Health Orgnanization)Articles on flood – 2022

Viewed on 25.04.2022 : https://www.who.int/health-topics/floods#tab=tab_1

3 FactsAbout Floods – Statistics & Data in 2022 - Financial Management of Flood Risk – OECD 2022

4 Idem above

5 Communiqué de presse - Les développements socio-économiques et les effets du changement climatique devraient tirer la hausse de la sinistralité liée aux événements météorologiques graves, d’après

SIGMA– SWISS RE - 2020

6 FinalReporton1998FloodsinthePeople'sRepublicofChina -OCHA(UNOfficefortheCoordination of HumanitarianAffairs) - 29 Sep 1998

1.1.2 Fig.1 : Numbers of people affected by weather related disasters from 1995 to 2015. (death are excluded from the total) - In the report of “The Human Cost of Weather Related Disasters” by the Centre for Research on the Epidemiology of Disasters – 2017

1.1.2 Fig.2 : Number of weather-related disasters reported per country (1995-2015) –reference same as above - 2017

1.1.2 Fig.3 : Number of floods from 1950 to 2009 by geographical regionTakeshi Fukao, 2012

1.1.2 Fig.4 & 5 : Bridge of Villegailhenc

France

River flood

Google map & Franceinfo, 2018

1.1.3 Communities flood danger

The sudden floods in urban areas are the most dangerous flood because they do not allow time to evacuate or protect flood-prone areas. Unfortunately, any type of flood is capable of happening suddenly in urban areas; it only depends on the location situation.

During a flood, the current or the waves can carry people away. All the built environment and especially the goods can suffer damage. Transport infrastructure is also vulnerable, especially bridges (see Fig.6 & 7). In addition, flood damage may persist (see Fig.8). Indeed, difficulties for users may remain after the flood, for example when certain lines of communication remain cut off until they are repaired. Or even the destruction of living spaces or supplies. When the water recedes is not immediate, the impacts of prolonged submersion are added to those caused by the current. Vegetation that has resisted the force of the current can wither if it remains underwater for too long, deprived of light and access to air.

Concerning the safety of the populations, the danger can come from the isolation imposed by a lasting flood, if drinking water or food are lacking. Secondly, flood is the main cause of population displacement in the world. It accounts for half of the 288 million people displaced since 2008 following a climatic event. Which is more than 60% displacement compared to wars or conflicts7 Industrial or technological accidents can also occur, caused for example by a failure of flooded safety systems. All economic activities located in flooded areas are impacted. Agricultural areas that are underwater can suffer significant losses. Worse, some health and safety hazards only become apparent once the water has receded. Contamination of drinking water distribution networks can cause housing to become unhealthy and develop mold, etc. Gas, heating, and electrical installations can be damaged and present a risk. As a result, it can be assumed that when urban flooding is occurring there is a growing source of social disruption, housing inequality, and significant economic loss.

The OCED categorized the damages into two groups : the direct losses (Casualties, injuries,economic,etc.)andtheindirectlosses(Emergencycosts,businessinterruption, etc ) 8 .

7 FactsAbout Floods – Statistics & Data in 2022 - Financial Management of Flood Risk – OECD 2022

8 Adaptation to climate change : soft vs. hard adaptation, Report, Stéphane Hallegatte and Patrice Dumas - CIRED and École Nationale de la Météorologie, Météo-France, 2010.

1.1.3 Fig.8 : Morlaix – France – River flood - Le Trégor, 2018

1.1.3 Fig.9 : Village evacuation during river flood in France – Firefighters photo, 2021

1.1.4 Flood hard or soft adaptation : Resistance and/or Resilience

he risk of flooding in terms of land use planning and management leads us to reflect on the modes of occupation, the growth of cities, and the necessity of planning and urban development for the communities living in these areas. However, we can say that flood is a well-known event all around the world. Consequently, flood risk management, event through its most simple form, exist since a long time.

Thus, it can be wondered, why the past flood risk protections & management aren’t efficient enough anymore ? Should we build higher and stronger, or does flood management need new strategies ?

Traditionally, society exposed to risk has tended to adopt a resistance strategy based on resistancealso called ‘hard’flooddefenses. Historically,citieshavetakenrefugebehind their walls to counter the risk of looting during wars. It was the same for natural risks. Consequently, the walls against flood became dykes. It was a matter of protecting oneself against the outside world by building a barrier sufficiently resistant so that the interior could be preserved from the damage caused by the risk. There is even an example of weaponized water in China where dikes of the Jing–Hang Grand Canal ( 京 杭大运河) were deliberately broken to flood and sweep away enemy' troops 9 . Moving water, and thus flood, was an enemy to be protected from or used to attack.That is what is named flood “resistance” strategy in western countries.

The construction of these resistance / hard adaptation strategies and equipment presents two major problems. Firstly, these infrastructures are designed to manage exceptional crises which can sometimes only occur once a decade, or even a century10 . Now, what to do with a wall or a dyke in a normal situation? How to integrate it into the city, to ensure that the equipment does not constitute a fracture in the urban form. Secondly, the risk is never completely predictable or controllable, as evidenced by many events such as the Katrina disaster in New Orleans in 2005 and Fukushima in 2011, to name only the most recent. Natural risk, and especially flood risk, is partly unpredictable and therefore cannot be fully controlled.

9 Cognition and Protection of Urban Heritage of Beijing-Hangzhou Grand Canal - 京杭大运河城市遗

产的认知与保护

- 武廷海，王学荣 -

2014

10 RESILIENCE STRATEGIES FOR FLOOD RISK MANAGEMENT UNDER UNCERTAINTIES

Karin M. DE BRUIJN - Delft University of Technology, Department of Water Management, Civil Engineering

Netherlands - 2004

Thus, this strategy of resistance raises both qualitative and quantitative issues. On one hand, it is a question of knowing how to enhance the tools of risk management to turn them into amenities within the urban form; on the other hand, it seems necessary to rethink the traditional management of risk, which seems increasingly unpredictable and extreme,nowmorethaneverwiththeclimatechangecontext.Tomeetthesechallenges, a new approach has emerged during the 2000s, initially in the research community, then within stakeholders : it’s the “soft” adaptation or also named “resilient strategy”.

“Summarizing, resilience against flood waves can be defined as the ease with which the system recovers from floods. In contrast, resistance against flood waves can be defined as the ability of the system to prevent any reaction to or impact from flood waves.” 11

Floodriskmanagement withsoftadaptation–resilience-isnowaquestion ofaccepting the risk, instead of trying to prevent it from occurring and to include it as a component in its own. The main losses during and after flood is the human casualty and the economic one. The resistant strategy is effective most of the time however, even when working correctly it does give less time to adjust flood consequences then resilient strategy (see Fig.11).

While the use of only resilient strategy is discussed as the best possibility for flood management, both strategy can work perfectly well together. The hybrid resilience/resistance strategy is probably the most used and present the best outcomes so far due to the past flood strategy been mostly resistant equipment. At least, it does have a better tolerable social/economical fluctuation (disturbance severity) than using only resistance strategy (see Fig.12).

11 RESILIENCE STRATEGIES FOR FLOOD RISK MANAGEMENT UNDER UNCERTAINTIES

Karin M. DE BRUIJN - Delft University of Technology, Department of Water Management, Civil Engineering

Netherlands - 2004

1.1.4 Fig.1 : Resilience VS Resistance –Introduction to Flood Resilience -2003

1.1.4 Fig.2 : Compare between resilience and resistance city - Sustainable and Resilient Landscape Design to Flood ( Case Studies: Resilient Projects in China) Samira Ahmadkhosravi – 2018 (redraw by author for better visualization - 2022)

1.1.4 Fig.3 : The relationship between reaction amplitude and disturbance severity for a resilient and a resistant system and a system that has both system properties - RESILIENCE STRATEGIES FOR FLOOD RISK MANAGEMENT UNDER UNCERTAINTIES- Karin M. DE BRUIJN - 2004

1.2 Research Questions

Theobjectiveofthis studyis to analyzetheresilientstrategyapplied tocommunities to make a list of built-environment elements helping to strengthen flood risk management and adaptation. The goal is to help communities to adapt to a new climatic reality by modifying town planning and construction practices favoring scalable and modular strategies. To achieve that goal many countries have developed resilient strategies applied to the built-environment because urban floods are the most dangerous. The wanted result is to strengthen the culture of risk prevention and infrastructureagainst risks. But also to ensure theadaptation ofpublicspaces to thenew conditions of the climatic issue with ensuring the resistance of society to various damages. Plus, the appropriation of risks by the actors of the territory, who have a preponderant role to play in the implementation of adaptation strategies according to local specificities. But how to support those soft adaptation / resilient strategies ? What was or can be done to create flood resilient communities ?And the most important :

How the influence of the built environment can improve communities to be more flood resilient?

Which gives the following inquiries :

- Which communities are more vulnerable to flood risk ?

- What is the type of flood resilient built environment in those communities ?

- What are the most important built environment factors to influence flood resilience ?

- Which one of those factors adds vulnerabilities or resiliencies and why?

This master thesis, by looking into the built-environment resiliency and how / why it influences the community flood risk, will demonstrate how endangered communities are protected.

1.3Aims and significance

This research aims to find a significant list of functioning exiting flood resilient strategies in the built environment. Those elements will come from historical backgroundandthesoft/resilient strategyapplied inthosepast yearsin the communities studied. In many countries, there is laws and regulations created to prevent or protect communities from a flood. Yet the “living with water” 12 concept and the resilience/soft

12 “Embracing Cultural Adaptions to Floods” definition from : Designing with water creative solutions

adaptation used for flood risk management for the past 20 years in western countries still need long-term experiences. “Moreover, most analysis has so far been based on a static approach and neglects long-term as well as short-term dynamics in hazard, exposure, and vulnerability […].” 13 .

About the significance, not only does community resilience need practical long terms projects to be optimized but specific case study research to add new elements to the fields. With the past event of the 20th century and its repercussions on flood events, making communities more resilient is now an important part of urban development and territorial management for many countries.

1.4 Keywords & Definitions

Definitions of this master thesis’keywords are established to enhance its meaning. The main words are : Resilience, Vulnerability, Flood risk management, Builtenvironment, Community, and Community resilience.

Resilience :

The concept of resilience in this master thesis questions the way of thinking about town planning and its capacity to adapt through disturbances. Resilience as a word has many definitions. However, for this study, resilience is the enhancement of built environment and its community's fast recovery from flood events. It is a very new experience and part of the “living with water” trend that started around 50 years ago 14 . Even if the word “resilience” is coming from the Latin word “resilire, resilio”, meaning “bounce”15 here, it will only be used as a new tool / philosophy for flood risk management.

At the scale of a city or urban system, resilience in the field of risk management is defined as the capacity to absorb a major disturbance like a natural disaster, by a return

from around the globe, Preparing for rising ride series, Volume 2, The Boston Harbor Association, SASAKI Firm,August 2014

13 Flood risk perception and adaptation capacity: a contribution to the socio-hydrology debate, Sven Fuchs- Konstantinos Karagiorgos- Kyriaki Kitikidou- Fotios Maris- Spyridon Paparrizos- & al. Hydrology and Earth System Sciences, European Geosciences Union, page 3184, 2017

14 “Many students of the robustness of people, objects and systems believe that “resilience” was coined by C. S. Holling in his landmark 1973 paper on systems ecology (Holling,1973)” Resilience and disaster risk reduction: an etymological journey ,Article, D. E. Alexander, Natural Hazard and earth system science - Institute for Risk and Disaster Reduction - November 2013

15 CNRTL, 2012 (consulted Fev.22.2022) : https://www.cnrtl.fr/definition/r%C3%A9silience

to a stable state. However, a “stable state” doesn’t always mean the previous state of the built environment. Nowadays, the city is wanted as the new ecosystem of the 21st century and community resilience is posed as a major condition for sustainable development 16 . Thus, resilience applied to communities in a flood risk management context becomes a necessity to understand vulnerabilities.

Vulnerability (ies) :

While resilience examines the way of thinking about the urban system and its disturbances, vulnerability is the degree of exposure of the built environment to damages. Vulnerability from a town planning point of view will be used to describe three physical factors : the exposure (damages, duration of disaster...), the susceptibility (protection, local sensitivity, accessibility...), and the adaptative capacity (available resources, capacity...) 17 . The vulnerability is more a tool for this study to discover the opportunity of flood than an element to withdraw.

Flood risk management :

This field aimed to identify, evaluate, and prioritize the risks associated with floods, no matterthenatureororiginoftheserisks,thentreatthemmethodically.Usually toreduce and monitor the possible disaster events, and their influence on the built environment. Flood risk management is often described through a specific cycle. The risk management cycle includes four general phases : Prevention, Preparation, Response, and Recovery.

- Prevention is aimed to warn and prepare the population and stakeholders ;

- Preparation is the set of measures before the risk aimed to avoid or reduce the impact during the risk ;

- Response is the actions taken during the risk ;

- Recovery is related to all post-crisis actions. It is often a long-term period.

Built environment :

The built environment is the space and elements in which communities are living.

16 Resilience-Oriented Urban Planning - Theoretical and Empirical Insights, Springer International Publishing,Ayyoob Sharifi, Yoshiki Yamagata, Fev. 20, 2018

17 Procedia Engineering, Volume 192, Pages 307-312, Chapter: Vulnerability of the City Infrastructure as a Part of the Resilient City Concept, Ján Havko, Michal Titko, Jana Kováčová, 2017

Community :

The Cambridge dictionary definition of “Community” is describing it as : “ the people living in one particular area or people who are considered as a unit because of their common interests, social group, or nationality ” 18 . This definition let the scale of this study bechosen between themacro,meso,andmicroscale.FromthePIRSmethodology, the scale of this study is within the city administrative limits. Then our community is people using the built environment of the town planning policies case study limits, also often known as the cadastral limit.

Community resilience :

The communities in flood risk areas are highly influenced by the reaction of their built environment. Thus, those past years, the built environments of metropolitan areas like Paris and its suburbs, rapidly changed in response to urban development dynamics, especially for risk management. The built environment of endangered communities includes all the human-made physical spaces where we live, recreate, and work. These include buildings, furnishings, open and public spaces, roads, utilities, and other infrastructures. These structures and spaces can affect the flood influence and so on the communities' resilience.

18 Cambridge Dictionary : https://dictionary.cambridge.org/fr/dictionnaire/anglais/community (consulted on Fev.18.2022)

1.4 Fig.1 : The risk management cycle - Atkinson et al, 2006

1.5 Methodology

The methodology is divided into four parts :

1- The literature review : To provide an overview of current knowledge on flood which allows the identification of relevant theories and gaps in the existing research, all around the world and the French government.

2- Mapping analysis : Second-hand data visualization through maps and plans (SIG software).The goal is to understand the flood risk context in Ile-de-France Region It analyses the existing resilient built environment, their communities, and where to find them.

3- On-site survey : To investigate the built environment data of the selected cases and the past or existing resilience.

4- Questionnaire with semi-structure interview : Explore local residents’ point of views and experiences.

1.6 Framework

To define the key concepts of the research, this master thesis framework is divided into two parts, the process (Research problem, methods and contribution) and the research steps (define approaches, understanding, explore and explain a scenario) :

1.6 Fig.1 : Master thesis Framework - Personal table made with VUE – G.C. - 2022

LITERATURE REVIEW

2.1 Introduction

2.2 Type of flood

2.3 Flood & Built environment

2.4 Resilience & flood management

2.5 The dark side of resilience

2.5.1 The definition : Opposition between resilience & resistance

2.5.2 The "return to normal" state issue

2.5.3 Risk of stagnancy & Resilience instability advantage

2.5.4 Social bias

2.5.5 Relying only on the engagement of local communities

2.6 Community Resilience

2.7 Literature review conclusion

2. LITERATURE REVIEW

2.1 Introduction

This literature review is providing a foundation of knowledge on the flood topic. It focuses its research on the main keywords of this master thesis : Resilience, Flood, Flood risk management, Built-environment, and Community resilience. Already presented and defined in chapter 1.4. The literature review of those concepts draws up a state of the art on the major cultural, scientific, and technical approaches to it and the main point of view from peers.

Beware : because the case study location is based in Europe and the authors of this master thesis can only read French and English, most literature review has – often - a western country's point of view.

2.2 Type of flood

Flood is an overflow of water that submerges land that is usually dry. Floods events can be categorized into 6 types :

1- River flood (see Fig.1)

“A fluvial, or river flood, occurs when the water level in a river, lake or stream rises andoverflowsontothesurroundingbanks,shoresandneighboringland.Thewaterlevel rise could be due to excessive rain or snowmelt;” 19

2- Coastal flood (see Fig.2)

“Coastal flooding is the inundation of land areas along the coast by seawater. Common causes of coastal flooding are intense windstorm events occurring at the same time as

19 Three common types of flood explained. Flood and water damage - Z.Zurich- July 22, 2020

https://www.zurich.com/en/knowledge/topics/flood-and-water-damage/three-common-types-of-flood

high tide (storm surge), tsunamis.;” 20

3- Reservoir flood also known as flooding from breaches (see Fig.3)

“Reservoirs are artificially created ponds or lakes that are usually formed by building a wall, knownas adam, across ariver. Ifoneof these dams failedthenwater could escape from the reservoir, resulting in land or properties being flooded;” 21

4- Sewer flood (see Fig.4)

“Sewer flooding can be causedwhenadrain or sewerbecomes full dueto heavyrainfall and overflows either inside a property or outside in the garden, street or other public areas. Drains and sewers can also become full when something blocks them and they become choked;” 22

5- Groundwater flood (see Fig.5)

“Flooding from groundwater can happen when the level of water within the rock or soil underground – known as the water table – rises. When the water table rises and reaches ground level, water starts to seep through to the surface and flooding can happen. This means that water may rise up through floors or underground rooms such as cellars or basements;” 23

6- Surface water flood (see Fig.6)

“Surface water flooding is what happens when there is too much rain for the drains and the streets fill with water.” 24

When discussing floods, it’s important to understand the multiplicity of it. Indeed, different types of floods can happen at the same time. In all those definitions there is only one truly necessary for the research : the river flood. Because it’s this master thesis studied type of flood.

20 Three common types of flood explained. Flood and water damage - Z.Zurich- July 22, 2020

https://www.zurich.com/en/knowledge/topics/flood-and-water-damage/three-common-types-of-flood

21 Flooding & Reservoirs - Gateshead Council - 2020

https://www.gateshead.gov.uk/article/3603/Flooding-Reservoirs

22 Sewer Flooding - Scottish water – 2020

https://www.scottishwater.co.uk/your-home/your-waste-water/sewer-flooding

23 What is groundwater flooding ? - EnvironmentAgency - 23 December 2019

https://environmentagency.blog.gov.uk/2019/12/23/what-is-groundwater-flooding/

24 Surface water: The biggest flood risk of all - Sir James Bevan KCMG, Chief Executive, Environment Agency, CIWEM Surface Water Management Conference - 17 October 2018

https://www.gov.uk/government/news/surface-water-the-biggest-flood-risk-of-all

2.2 Fig.1 : River flood – Paris, France – 2016

2.2 Fig.2 : Coastal flood – Fréjus, France – 2011

2.2 Fig.3 : Dam failure flood – Hérault, France – 2008

2.2 Fig.4 : Sewer flood – Malestroit, France – 2019

2.2 Fig.5 : Groundwater flood– Diebolsheim, France – 2021

2.2 Fig.6 : Surface water flood – South of France- Fotolia – 2022

2.3 Flood & Built environment

The built environment encompassing the buildings people live in, the water and electricity distribution systems, the roads, bridges, and also transportation systems. It is usually described as a modified or man-made space providing people. In literature, the built environment in the context of flood is described as : “ […] generally about buildings and infrastructure for example; transports, energy, water, waste and related services. Commercial properties and construction industries are also considered.” 25 . Consequently, flood built environment is all man-made structure in the surroundings of flood areas. Those flood risk areas are usual determined by a flood risk prevention plan orknown by the local communities. Whileit is not always impossibleto build in a flood zone, in many countries it depends on the level of risk. Then why a large part of the world population are still living in flood areas and are affected by its damages ?

Unfortunately :

1- The flood risk areas aren’t always known. Example : Urbanized areas on dry land that became flood area, new urbanized zone on unknown flood area, climate change uncertainty, urbanization impact, etc ;

2- Many floods factors comes from the weather which is not always predictable ;

3- Flood risk areas are moving with their environment ;

4- New challenges like climate change, population rising, etc, are increasing the vulnerabilities;

5- Living in front, or near, rivers, oceans; etc, is considered like a high quality of life. Therefore, more people does live near or in risk areas ;

6- Stakeholders and states doesn’t always warn and / or protect the population or the built-environment on those flood risk areas (because of money, capacity issue, knowledge, etc.) ;

7- There is often discrimination against the population most endangered by floods (low income communities).

Furthermore, the implementation of certain or the use of development techniques such as dikes and flood control dams protection – hard adaptation / resistance strategy- often

25 Design ofASustainable Building:AConceptual Framework for Implementing Sustainability in the Building Sector, Peter O.Akadiri, EzekielA. Chinyio, Paul O. Olomolaiye, Buildings 2012, 126-152, 4.May 2012

encourage populations and officials stakeholders to urbanize flood-prone areas, convinced that the risk has become acceptable 26

2.4 Resilience & flood management

From the different literature, the word “Resilience” has been and continues to be, defined in different ways. The term “resiliency” is used at least since the 18th century in Great Britain. In 1901 it was only defined through the science of materials and physics as being the capacity of a material to resist a rupture.

In western countries, it’s the environmental scientist C.S. Holling, who defined resilience in 1973 as “a measure of the persistence of systems and of their ability to absorb change and disturbance and still maintain the same relationships between populations or state variables.” 27 The field Holling promoted was ecological economics and he tried to applied this concept to the management of natural resources.

Since, the concept of resilience has gradually evolved when adopted by other disciplines like psychology, ecology, economics, individuals, ecosystems, urban systems, etc.

Nowadays, the evolution of resilience in flood risk management is deeply linked to the notion of “living with water”. The way articles and other writings are describing the subject shows the recent general acceptance of floods as a positive event : “ […] the aim is no longer systemically to reject water, but to accept it into the territory and adapt.

[…] There is a conceptual shift from resistance towards resilience […].”

28 Resilience is often given as a solution opposed to risk resistance : “The standard approach to flood risk management (FRM) amongst developed nations has often been the adoption of resistance-based strategies. [...]. Although this approach can provide substantial protection against floods [...] it does not cope well with uncertainty.”29

26 Chapitre 2 : L’intégration matérielle du risque par le biais des mesures structurelles, Environnement et société, Edition Presses universitaires du Septentrion, Helga-Jane Scarwell, Richard Laganier, p. 117-162 , 2004

27 Foundation of Ecological resilience – seminal paper - edited by Lance H. Gunderson, Craig R.Allen & C.S. Holling - 1973

28 Conception par l'opportunité pour des villes éco-résilientes aux inondations, Emilie Gascon's Thesis, p14, 2017

29 A review of the flood risk management governance and resilience literature , Article, Journal of Risk management - The chartered institution of water and environmental management (CIWEM) and John Wiley & Sons Ltd, page 291, 2017

Both resilience and the notion of risk acceptance are young ideas. All are related to subjects made in the last 50 years, if not less 30 . s a result, their practical application of them in real projects is few.

This isn’t specified clearly in the literature but the lack of long-term knowledge from proper examples is flagrant : ”It has been argued that learning from flood experience contributes to flood resilience. However, it is unclear what such a learning process involves […].” 31 . The methodology of flood resilience for FRM32 is already debated among the literature sources. Thus, many research could appear to have disconnected and hypothetic from one another. Yes, flood events happen, but the “resilience solution” is missing long-term practice. “ […] design and evaluate alternative flood risk management strategies […] are applicable for the long-term (50-100 years).” 33 Therefore : “The long-term success of such framework and initiative hinges [...] FRM resilience.”34 .

Following the same path, urban resilience, the union of resilience and town planning, is an even more recent concept, which like its predecessors remains to be clarified and in cruel need of long-term data. While there are many literatures in a variety of disciplines on the subjects of resilience and territory, their use may seem very conceptual. It could even be described as quite remote from field concerns and difficult to apply on-site.

Still, a rise of resilience in the post 10 years constitutes a tool of prime importance in flood risk management : “ […] there is a growing emphasis on enhancing the resilience of cities in the face of unprecedented urbanization and climate change.” 35

30 Resilience and disaster risk reduction: an etymological journey ,Article, D. E. Alexander, Natural Hazard and earth system science - Institute for Risk and Disaster Reduction, University College London, London, UK , page 2708, Published: 5 November 2013

31 Learning from Floods: Linking flood experience and flood resilience, Article, Journal of Environmental Management,n° 271, Da Kuang & Kuei-Hsien Liao,page 8, October 2020

32 Flood risk management

33 Living with floods - resilience strategies for flood risk management and multiple land use in the lower Rhine River basin ,Article, Michaël Van Buuren, Marinus Vis, F. Klijn, Alterra - IHE - RIZA - TUDWL|Delft Hydraulics, page 2, January 2002

34 A review of the flood risk management governance and resilience literature , Article, Journal of Risk management - The chartered institution of water and environmental management (CIWEM) and John Wiley & Sons Ltd, page 300, 2017

35 Defining urban resilience : A review, Article, Landscape and Urban Planning, Volume 147, Pages 3849, S. Meerow, J.P.Newell & Melissa Stults , Marsh 2016

Urbanization andclimatechangeareverywellknowntohaveheavyinfluencesonflood. Indeed, urbanized areas, and so on the built environment, are highly vulnerable because they concentrate populations, sometimes political power, economic centers, and highly interconnected networks. Cities’built environment and communities can be affected by the very mobilizing brutal crisis.The real dilemma remains in the long time events even more because the population and stakeholders stop perceiving the crisis event as a risk when it’s the most important moment to apply risk management.

We can summarize the literature review on flood resilience as emerging and in need of development and recognition from both public and private stakeholders. It also demonstrates the difficulty to compare and gather information in this field study.

2.5 The dark side of resilience

2.5.1 The definition : Opposition between resilience & resistance

Although this master thesis uses only one definition of "resilience" (see chapter 1.4), there are several of them. The “resilience” different definitions are not always compatible and often rise to very agitated debates 36 .

The contradiction and opposition are mostly between resilience and resistance (soft and hard adaptation). For some, their definitions are identical but that’s because they confuse resistance and persistence by implying that persistence refers to strength and toughness 37, exactly what Holling wanted to overcome in 1973 38 For others, these two notions are distinctly different. For them – and this master thesis - resilience (soft adaptation) is based on adaptability and therefore implies flexibility, while resistance (hard adaptation) implies opposition and rigidity. That is why the use of “soft” and “hard” adaptation is more accurate when referencing the resilience / resistance debate.

The master thesis will continue using the words resilience and resistance because they are the most used in western literature when discussing flood risk management.

36 Resilience definitions, theory, and challenges: interdisciplinary perspectives - Steven M. Southwick, George A. Bonanno, Ann S. Masten, Catherine Panter-Brick, and Rachel Yehuda – Article in Eur J Psychotraumatol - 2014

37 “ What Resilience Is Not: Uses andAbuses” Ce que la résilience n’est pas, ce qu’on veut lui faire dire, Géraldine Djament-Tran,Antoine LeBlanc,Serge Lhomme, Samuel Rufat,Magali Reghezza-Zitt, p23/ 24 - 2011

38 Foundation of Ecological resilience – seminal paper - edited by Lance H. Gunderson, Craig R.Allen & C.S. Holling - 1973

2.5.2 The "return to normal" state issue

Following the precedent literature review, the resilience concept is shaping a renewal of flood risk strategy approach. Because the concept of resilience raises an important issue of definition, it is not certain that all those who use the term mean the same thing. The lack of recognition of private stakeholders illustrates the missing culture of it in mainstream architecture and urban fields. Consequently, the official responses to flood crisis are seen as a “return to normal” event. The normality bias leads us to believe changes are temporary and the future will be like the past.

The return of the expected equilibrium through the capacity to be resilient is a debated subject. Some want a return to the “before” state and others wish to change this state which represents an imbalance that directly led to the flood crisis : “[…] flood resilience policy flood damages have to be minimized and normal life has to return as soon as possible after flood.”

39 .

In that case, one can wonder what is a “normal” period?

In "Defining urban resilience : A review” S. Meerow and J.P.Newell present the situation as follow : “But what if the original state is undesirable? Certain conditions (e.g., poverty, dictatorships, fossil fuel dependence) can be highly undesirable yet quite resilient.” 40

When looking at official responses to flood resilience, the stakeholders always refer to resilience as the ability to “return to normal”, despite the shock.

However, resilience is the ability of a system to return to a state of equilibrium after a disturbance. It doesn’t mean that the state of return has to be under the same circumstances as before the crisis. In 2013, Wagner and Breil defined resilience as “ […] the time required to return to a previous stable state after a disturbance […] ”

41 , when in 2020 the subject changed to “ […] disaster experience provides the opportunity to learn about recovery and could inspire the public to demand new

39 From Hamburg University of Technology’s flood management website : http://daad.wb.tuharburg.de/ (consulted on Fev.12.2021)

40 Defining urban resilience :Areview,Article, Landscape and Urban Planning, Volume 147, Pages 3849, S. Meerow, J.P.Newell & Melissa Stults , Marsh 2016

41 The role of ecohydrology in creating more resilient cities, Iwona Katarzyna Wagner & P.Breil,,

policies or tools to enhance recoverability.” 42 from D.Kuang & Kuei-Hsien Liao article. Exactly like with the “living with water” concept, the point of view is shifting.

Progressively, literature on the subject is taking into account the impossibility to return to the living conditions that prevailed before the occurrence of the disaster. Kenji Fujiki in his thesis describe : “ […] the post-crisis does not consist of returning to a static point in time, but on the contrary represents a dynamic process […]“43 .

Unfortunately, the “return to normality” is still nowadays the objective displayed by manyauthoritiesabout floodresiliencewithout real description ofwhich stateis wanted for the post-crisis moment. (example ? see below?) Furthermore, those debates in the literature field raise a logical question : what is a desirable state for resilience, and for whom? Talking about resilience requires at least identifying the system that is undergoing the crisis, identifying what the crisis is, who named or defined it as such, what are its spatial and temporal limits, and its characteristics. The French government’s booklet from the Ministry of Ecology, Sustainable Development and Energy in 2014 writes about it in those words : “ […] to project towards a normal, ideal or sustainable state supposes defining these states and to rely on a shared project of society.” 44 In their article, the authors of “What Resilience Is Not: Uses and Abuses” give the example of Bucharest slums (see Fig.1 & 2) where the territory stakeholders, who seek to impose their urban project, do not use the concept of resilience because it is the concept of the “bad” city. 45 Indeed, the slums in Bucharest are the best Ecohydrology & hydrobiology, Volume 13, Elsevier, p114, December 2013

42 Learning from Floods: Linking flood experience and flood resilience,Article, Journal of Environmental Management,n° 271, Da Kuang & Kuei-Hsien Liao,page 8, October 2020

43 Prospective study of the social impacts of a major flood in the Ile-de-France region. Socio-spatial disparities in the care of Ile-de-France populations in crisis and post-crisis situations: a mapped and quantified analysis of household needs, from evacuation to reconstruction – CHAPTER 4 - The postdisaster reconstruction strategy - Kenji Fujiki, Thesis , Geography. Université de Lyon (Université Jean Moulin Lyon 3), 2017.

44 Translated by the author of this master thesis, G.Charreau from : La résilience, un outil pour les territoires ? Article published during the IT-GO Rosko 2014 seminar, Roscoff, May 22-23, 2014, Clara Villar et Michel David, 20 août 2014 : https://www.cerema.fr/fr/actualites/resilience-outil-territoires (consulted onApril.6.2021) Original statement : “Se projeter vers un état normal, idéal ou durable, suppose de définir cet état et de s’appuyer sur un projet partagé de société. »

45 “ What Resilience Is Not: Uses andAbuses” Ce que la résilience n’est pas, ce qu’on veut lui faire dire, Géraldine Djament-Tran,Antoine LeBlanc,Serge Lhomme, Samuel Rufat,Magali Reghezza-Zitt, hal-00679293, p 23/ 24, 2011

representation ofurban resiliencemadeto operateinadegradedsituation, making quick reconstruction.

Theslums ortherefugee camp areagoodexampleofresiliencebecausethey arealways reborn with light materials, without networks, viability, or the issue of ownership.

“ But if the “good” city of the town planner is “resistant”, the “bad” city of the mahala (the slums), is resilient, because although periodically destroyed, it redeploys quickly after each trauma. ” 46

46 Idem above. Translated by the author of this master thesis, G.Charreau. Original statement : Mais si la “ bonne ” ville de l’urbaniste est “ résistante ”, la “ mauvaise ” ville des mahala, est résiliente, car bien que périodiquement détruite, elle se redéploie rapidement après chaque traumatisme […] » p24

2.5.2 Fig.1 : Bucharest Romanian capital slums before flood – 1970

2.5.2 Fig.2 : Bucharest Romanian capital during flood - 1970

In this context, resilience is “bad” when it restores things that don't workor areharmful, but that is also a political point of view. In S. Meerow and J.P.Newell‘s article the issue is stated as such : “ Not all stakeholders will benefit equally from resilience-based actions, and the concept may be used to promote a neoliberal agenda or retain systemic inequality […] ”. 47

Consequently, resilience isn’t only at the level of the built environment. It implies a part of forgetting, which allows reconstruction, a part of adaptation and imposes a change in built environments. It is no longer so much a question of characterizing a physical-socio-spatial system as resilient or not, but of analyzing what changes and what is maintained in this system confronted with a crisis, and above all an understanding of whom and for what.

2.5.3 Risk of stagnancy & Resilience instability advantage

As a result, the main issue with the use of an identical definition for resilience / resistance and a “returntotheold state” point ofviewis thestagnationofvulnerabilities.

The use of resilience as a synonym of resistance doesn't show the possible reversal of the paradigm it gives to help human societies flood adaptation. This desire, is also related to the "return to the old state" to keep the past resistant strategy while raising the risk and impacts. It prevails the societies to accept the risk and thus, don't prevent it from occurring. It also includes the non-recognition of territories and community changes.

The built environment isn’t static. It moves like and so does flood. Adaptation and risk managementarechangingwith peopleandsociety. Hollingevenreferred to theresilient system not by preserving a single state of equilibrium but by passing through different states of equilibrium, stable and unstable 48 .

To illustrate, communities in floodareas in India are more flexible when the destruction of their built environment happens. When flood destroyed their houses or living spaces – which is often - they rebuild them rapidly and easily. The material, bricks, would

47 Defining urban resilience :Areview,Article, Landscape and Urban Planning, Volume 147, Pages 3849, S. Meerow, J.P.Newell & Melissa Stults , Marsh 2016

48 A typology of resilience : rethinking institutions for sustainble development - John W. Handmer & Stephen R.Dovers -Australian National University - 1996

permit a quick adaptation to the territory 49 . Moreover, the reconstruction is re-using displaced materials found after the floods (see Fig.1) The local religion and philosophical mindset are also helping because closer to the resilient strategy “living with water” style. Like Lavoisier said : “Nothing is lost, nothing is created everything is transformed.” 50

Inopposition,theresistancestrategyismorestagnantthantheresiliencestrategy.While the resilient strategy does have a deeper impact during floods than the resistant strategy failure, the losses and territory adaptation are reducing the impact in the long term (see Fig.3).

Resilienceis, comparetoresistancestrategy,aflexibleandadaptablesystem preventing with long term strategy. Especially because the resistance doesn’t enhance flood risk culture.

– 2021

49 Flood-resistant housing attracts attention in Kerala -Article - Mongabay - by K. Rajendran on 24 July 2019

50 French chemist Antoine Laurent de Lavoisier, born in 1743. With his experimental method, Lavoisier helped establish modern chemistry.

2.5.3 Fig.1 & 2 : Artisanal brick creation & A brick house re-built after flood – India

2.5.4 Social bias

"It is not the hazard that creates the disaster, but the social, economic and political structures experienced on a daily basis." 51

The social-economic inequality in society restricts access to resources and protections forlow-incomepopulations.Asaresult, this prevents some communities from implementing adaptation measures. It isalsodiscriminatory,bothsociallyand spatially, because access to resources is not equal for all. Vulnerability is therefore closely associated with the issue of poverty. Poor people have less access to capital to cope with the

51 Prospective study of the social impacts of a major flood in the Ile-de-France region. Socio-spatial disparities in the care of Ile-de-France populations in crisis and post-crisis situations: a mapped and quantified analysis of household needs, from evacuation to reconstruction - The post-disaster reconstruction strategy - Kenji Fujiki, Thesis , Geography. Université Jean Moulin Lyon 3 - 2017.

2.5.3 Fig.3: Graphical depiction of resistance versus resilience in response to functional service provided (y-axis) and time (x-axis) - Stovall – 2012

hazard, have less social capital to mobilize during reconstruction, are more politically isolated, and therefore less able to receive external aid. The disaster is therefore not caused by a bad choice in terms of adaptation or adjustment but by the impossibility of making these choices. Thus, the structuralist approach prefers soft adaptability or resilience over the hard strategy / resistance.

However, a resilient strategy - in definition supposedly low-income inhabitants more friendly than resistant – can succeed in the protection of the built environment and fail at social protection equity. To illustrate, the example of the Netherland is blatant : In her thesis, Siyu Yu, PhD, present the analysis of resilient plan policy from Nijmegen city. Her conclusion can also be regrouping the point of view of social protection from the Netherland : while heavily using flood resilient strategy it doesn't target highly socially vulnerable neighborhoods 52 (see Fig.1). This type of mistake from countries using resilient flood risk management is quite common, unfortunately 53

2.5.4 Fig.1 Analysis of resilient plan policy

2.5.5 Relying only on the engagement of local communities

The last problem is link to political management scale. The resilient adaptation involvement from the scale of governmental or analytical framing seems to run scarce.

Even if the development of resilience and its rapid spread through countries' policies sincethe2000shighlightsadesiretouseamoreresilientstrategy,thescalemanagement shows a disconnection between national and local flood risk strategies. The new system understands and develops a range of adaptive approaches but political adaptation seems to be criticized by societal and political theorists. They mostly condemned resilience communication for its implication with the neoliberal ideal 54

52 Planning for resilience and climate change in the U.S. and the Netherland - Siyu Yu, phD, AICPTongji - 2021

53 NOACCIDENT, Resilience and the inequality of risk - Briefing paper - Oxfam - 21 May 2013

54 “The argument of this conclusion is that approaches attuned to the centrality of the Anthropocene provide a critique of the politics of adaptation which is much more powerful than that levelled by critical societal and political theorists who have, over the last decade, condemned resilience discourses for their imbrications within neoliberal paradigms (Chandler, 2014Chandler, D. (2014). Joseph, (2013); Walker & Cooper (2011); Evans & Reid, (2014)” - International Policies, Practices and Discourses - Volume 7 -

Issue 3: The Politics of Resilience, Edited by: Clemence Humbert and Jonathan Joseph Resilience: Article , The governance of complexity – David Chandler - Pages 304-313 - 2019

Exactly like the social issue from the last chapter 2.4.4, if the communities can’t afford to choose protection because of money, they are left to face danger and losses alone. Even if new scale management could be a part of an interesting resilient strategy, considering the challenges of catastrophic global warming, it only looks like disengagement from the government.

Indeed, the problems facing adaptation today are primarily economical, government doesn't want or/and can't be involved more than necessary because of budget. Consequently, the last decade of flood risk management often relies on the engagement of local communities. It happens in France with the delegation of some flood risk management to the EPCI (Public institution for inter-municipal cooperation). Which, with time only proves the lack of resources from the communities to adapt themselves.

The policy-making response to this can also be the development of greenwashing documents and rules, like in France. In 2016 is published in France the “Charter of commitment to "design resilient neighborhoods" facing risk of flooding” (see Fig.1) . The charter is only 7 pages long and avoids any technical explanation. It also doesn’t come with any repercussions if architects or mayors want to build vulnerable housing in flood areas, create permeable pavement, or destroyed green areas 55 That type of low involvementislong behindprojects likethespongecityprogram lunchin 2011in China (see Fig.2).

In general, the reliance on only one type of management scale or even strategy is linked to failure and when it does; it can be devastating. In Germany, the territory isn’t yet fully adapted for floods and climate change disturbance. What happened during the flood of June 2021 (see Fig.3 & 4) is both related to a failure of territory adaptation and the weather warning system 56 . Both the government and the communities were supposed to verify if the warning system was operational, turned out, it wasn’t.

55 Note from the author : Obviously other regulations and policies are dedicated to that, but even then they aren’t link to flood resilience but to other field. Example : green areas are sometimes under protection in urban local plan (PLU) but then why it doesn’t show up in the resilient charter of 2016 ? It’s like documents, policy or rules aren’t connected and show a poor investment on the subject by the government.

56 “Weather scientists say a ‘monumental failure of the system’ is directly to blame for the death and devastation triggered by a month’s worth of rain that fell in two days this week.” The Sunday TimesSunday 18th July 2021

2.5 5 Fig.1 French resilient charter - 2016

2.5.5 Fig.2 Sponge city China program example

2.5.5 Fig.3 : Town of Dernau, Germany, Gerhard Launer, April, 2007

2.5.5 Fig.4 : Town of Dernau, Germany, Ahr River flood, Police picture, July 2021

2.6 Community Resilience

Since the emergence of resilience / soft adaptation for risk management, the study on a community scale grew. “ Community resilience has emerged as a new concept over the last decade and has gained in importance as a key concept […] .“ 57 . For the most part, the research focus only on a specific field, it’s rarely multi-disciplinary but scholar research studies ask for it. “For the most part, recent review pieces focus only on a specific field. ” 58 . n architecture, the use of the community resilience scale is made to investigate the living environment. Link to resilience, the community scale risk management is a long-term period analysis.

Thereby, comparing different studies of community resilience is difficult. Because of its novelty, the stakeholders often fail to get correct data and strict frames in their methodology. Furthermore, the lack of acknowledgment of living conditions from before the crisis put another layer of missing information on the studies. It depends on the political goal of resilience for each stakeholder, but the tendency of the authorities to do so is common 59 . The field study of architecture and urban design is older and so on more detailed, which eases some methodological research parts. The main question now for community resilience is : how to gather and measure the community resilience ?

Since each flood and community is different, various methodologies exist but each research has its ownframeanddefinitions.Additionally,depending onthepolitical goal of resilience for each stakeholder, there could be a lack of community living conditions before the crisis. acknowledgment : “This […] ignore the social vulnerabilities shaping pre-disaster conditions produces what we might refer to as an “equity gap” in the contemporary resilience literature. “ 60 . All those key points of community resilience make the study of this subject a difficult one. In his review of a University’s disaster recovery tracking tool, B.Mayer suggests that “ […] even the most qualified disaster practitioners would likely face serious impediments in collecting sufficient data to complete such detailed assessment.”61

57 Community recovery and resilience building in the aftermath of flood hazards in the small island developing state of Mauritius,Anoradha Chacowry, The University of Gloucestershire, p.71, June 2014

58 Mayer, B. A Review of the Literature on Community Resilience and Disaster Recovery. Curr. Envir. Health Rpt 6, 167–173, 2019

59 Impacts of Missing Data in Risk Management - Thesis - PARIS 1- Patricia Dos santos - 2021

60 Idem above.

61 Idem above.

Despite the significant growth in resilience research, studies of community resilience practice remain comparatively scarce. Yet, the “built environment” part of it presents a large panel of possible research, data, and methodology.

2.7 Literature review conclusion

- The definition of “resilience” if often mistaken with the “resistance” one (see chapter 2.4.1).

- The idea of resilience / soft adaptation especially in western countries and risk acceptance as we know it and talk about in this research is quite new in the flood risk management field (see chapter 2.3).

-This means the research and existing project with this vision are few (see chapter 2.3).

- Town planning and more specifically resilience - in most western countries - are a long process.A10 to 50 years planning results (see chapter 2.3).

- The definition of resilience applied to floods isn't fully decided because the “normal” state of the endangered communities isn’t well defined either.There is two main vision, 1/ thereturnto the“before”stateofthefloodarea whichmeanrebuilding and recreating life exactly as before without changing flood strategy and question the flood causes, 2/ the desire to change the "before" state because it's recognized as a part of the problem (see chapter 2.4.2 example : Romania).

- Nowadays, for many reasons, the "return to rebuild the same built-environment as before the flood" is the main goal for resilience. It's obviously changing but most countries around the world still make mistake when using resilience strategy. There is different reason for that : economical issue, greenwashing, government disengagement from communities, failure to check warning system, lack of risk culture, etc. (see chapter 2.4.5 for examples : France & Germany)

- The literature review's general point of view talk about how resilience is criticized because of neoliberal ideal getting into the frisk management strategy (see chapter 2.4.5). The scientific definition – used for this master thesis – and the neoliberalism system are two opposed visions One of the results is a social bias that can be observed when dealing with flood risk management and socially vulnerable communities

(example the Netherland, see chapter 2.4.4).

- There are many reasons why flood resilience doesn't evolve despite the existing literature review on a possible better approach. (see chapter 2.4) But the number one is the loss of flood culture as a results of the industrial revolution and money issue.

- Building for flood community resilience is quitenew too.Then, gathering information and methodology is a bit difficult, but not impossible (see chapter 2.5).

- In town planning, the use of the community resilience scale is mostly made to investigate the built environment (see chapter 2.5).

LOCAL CONTEXT

3.1 Introduction of the Ile-de-France

3.1.1 Mapping methodology

3.1.2 First scale study area, the region Ile-de-France

3.2 Ile-de-France region flood

3.3 La Seine flood fluctuation

3.4 The historical 1910 flood damage and impact

3.5 Hazard flood map

3.6 Modern flood impact and losses - 2016 Flood example

3.7 Ile-de-France flood risk protection

3.8 Chapter conclusion

3. LOCALCONTEXT

« She goes to the sea

Passing through Paris

La Seine is lucky

She has no concerns

And walks between the quays

In her beautiful green dress

And her golden lights. »

3.1 Introduction of the Ile-de-France : first scale study area

3.1.1 Mapping methodology

All the maps from figure 3.2 to figure 4.4 (except 3.5 Fig.2 and 4.3 Fig.2) are made with the QGIS software made by myself, Gwendoline Charreau. All the information / data / references used to make them are written on it. They are not translated because it's their original name. However, to avoid misunderstanding and for intellectual transparency, their translation is as followed (for those needed and in order of appearance on the maps) :

1-Data.gouvLimitesDépartementalesetcommunales-2020: Data.gouvDepartmental and municipal boundaries - 2020

2- DRIEE cours d'eau Ile de France - 2020 : Regional and Interdepartmental Directorate for the Environment, Planning, and Transport - Watercourses in Ile-de-France (with flood data too)-2020

3- Découpe morphologique d'Ile-de-France - Data.gouv.fr - 2016 : Morphological

Jacques Prévert, Chanson de La Seine - 1945

section of Ile-de-France - Data.gouv.fr - 2016

4- Corine Land Cover - 2021 : Also called CLC, Free data of biophysical inventory of land use and its evolution.

5- Data.gouv.fr, Enjeu écoonomique, patrimoine et mobilité - 2013 : Economic stakes, heritage and mobility - 2013

All data used are (when possible and available) the newest data. The data creation’date are at the end of each of their named. The map not made by Qgis are named and their authors' names are in the legend for all of them (3.5 Fig.2 and 4.3 Fig.2).

3.1.2 First scale study area, the region Ile-de-France

The case studies of this master thesis are located in France, near Paris, in the region named Ile-de-France. Which by translation mean “The island of France”, not because it’s a real island surrounded by water but as a reference to the large number of rivers that cross the 12,000 km² of the territory : La Seine, L’Oise, La Marne, L’Essonne, L’Yrres & L’Yonne & some minor others 62 (see Fig.1).

With just over twelve million inhabitants, l’Île-de-France region is the most populous administrative region in France. Encompassing the city of Paris (2 million inhabitant) and seven districts called “departments”, all associated with different name and number fora total of 8districts : Paris(75) ; Seine-et-Marne (77);Yvelines (78); Essonne(91) ; Hauts-de-Seine(92) ; Seine-Saint-Denis (93) ;Val-de-Marne (94) ;Val-d'Oise(95) (see Fig.2). 62 L’Île-de-France

et les Franciliens - Xavier Panon – Decitre – France - 2004

3.1 Fig.1 Ile-de-France main rivers & waterways

3.1 Fig.2 Ile-de-France Region districts

Each of the 7 districts are divided in “commune”, it could be translate by ”administrative township limits” or “municipality”. There is 1268 municipalities in Ile-de-France (see Fig.3). Paris “municipalities” are named “arrondissement”, it is mostly a word used to describe an administrative subdivision of a large city.

L’Ile-de-France is a highly populated region It represents 18.8% of the population of France on only 2.2% of its area, which makes it the most populated region and the most densely populated in France 63 . However, the region density is obviously centered around Paris and what is called the Greater Paris Metropolis (le Grand Paris), which is located at the center of the region (see Fig.4).

The territory of the region is highly urbanized despite the large part of the territory ecological landscape fragmentation. 3/4 of the region is still covered with forests or agricultural land 64 (see Figs.5).

Fig.3 Ile-de-France – Administrative township limits / sub-district (Communes)

3.1 Fig.4 Ile-de- France – Municipality Density Population per Km²

3.1 Fig.5 Ile-de-France – Land use

3.2 Ile-de-France region flood

The risk of river flood in France and in the region Ile-de-France is the most important natural risk. The number of the damage it causes and the number of municipalities concerned, are very high. From a flood point of view, every type of land use can be vulnerable, whether it’s urban or urban areas, plains, hills or coastlines, etc (see Fig.1). From this map can be observe a lot of vulnerabilities around the centre on the urban fabric, which is the effect of the river La Seine mainly on Paris and its surroundings municipalities.

In Ile-de-France the major type of flood are the groundwater flood, the Surface water flood and, finally, the most dangerous, the River flood, especially those from the river La Seine.

3.2 Fig.1 Ile-de-France – Land use and built-environment (only economical / heritage and mobility) vulnerabilities

In 2012, the French government set new national criteria for characterizing the importance of flood risk 65. The areas are determined depending on the significant number of potential impacts on human health and economic activity. They are named TRI : A Territory at significant risk of flooding 66 . The “flooding” referred in the definition is manly river flood. This new determination for part of the territory makes it possible to both act where the issues are most threatened, and to act where there is the most to gain in terms of reducing flood damage. Like the vulnerability in Fig.1, most of the TRI are around La Seine (see Fig.2).

The TRI aren’t such a surprise because more than 25 major floods of La Seine have flooded the Ile-de-France since 1900.This means that 25 times themaximum water line (more than 5 meters) has been reached for the main floods in the Seine estuary since 1900. At more than 6 meters some important train lines are already closed and several communities – outside from Paris limits - have their homes in water.At more than 7.10 meters, the flood becomes "catastrophic" because it can strongly damage Paris, the capital of France.

Paris has often been the benchmark for action taken to protect inhabitant and builtenvironment from floods. It wouldn't be a problem if today with the urbanization, the increase of the population in flood areas, previously empty and the climate change uncertainty the multiplication of vulnerabilities rise every year. The vulnerability has therefore, increased and thebenchmarks for floodrisk management doesn’t always take into account those in need of it. It's important to also understand that the most endangered communities are mostly made of low-income people. Once again, like explained in chapter 2.5.4, there is a social bias in the risk management system, no matter the use of resilient strategy or not. When Paris witness a 5 meter flood, the suburbs are already underwater.

From its geographical and topographical location, the south of La Seine, named “l’amont” meaning “ coming from before” is always the first part of the territory to witness the rise of La Seine. Therefore, the territory named “La Seine amont” is the beginning of La Seine journey in Ile-de-France before reaching Paris at its center then continuing until the sea in the North of the Country (see Fig.3).

65 Arrêté du 27 avril 2012 relatif aux modalités de l'exécution de la mission de contrôle des installations d'assainissement non collectif – French Gov. - 2012

66 Territoires à risques importants d’inondation – French Gov. : https://www.grand-est.developpementdurable.gouv.fr/territoires-a-risques-importants-d-inondation-tri-r6724.html - visited the 30th ofArpil 2022

3.2 Fig.2 Ile-de-France – TRI areas and flood hazard

3.2 Fig.3 Ile-de-France – Topography with flood hazard & La Seine flow

3.3 La Seine flood fluctuation

L’Ile-de-France is the meeting territory of major rivers. For the most part, this catchment area is subject to oceanic influences which generate winter plain floods, generally predictable within a few days. However, summertime, with the climate change context does see an increasing number of flood. Therefore, floods often happen during winter and summer. It should be noted that La Seine floods are deeply connected to the other rivers around it, if flood is on those rivers, La Seine rise too. The flood on La Seine is very harmful because while the river flood the visible ground, the groundwater table flood harm buildings' structure and rises through sewers and caves, in non-flooded areas.

The river flood danger is measured by its flow. La Seine flow is up to 500 meters cube per second. Because a flood also corresponds to the increase in the flow of a river exceeding several times the average flow, when higher than 500 meters cube, a flood occurs in the territory near La Seine. This river flood is mostly slow, 50 cm per day maximum. Those flows reveal that La Seine has a natural flood system called the "return period". The return period is an average statistic time scale when an event of the same intensity occurs. This term is widely used to characterize natural risks such as earthquakes, floods or floods, storms, storms, etc. This notion is applied after the observation of flood events. Therefore, this statistical designation has no immediate predictive, nor periodicity value.

La Seine flood can be divided in 4 return period types :

1- The millennial flood : A 1000 year flood is a flood whose probability of occurrence over a year is of 1/1000 chance. In other words, each year, the probability that its flow will be reached or exceeded is 1/1000. Beware, it doesn't mean the flood happen every 1000 years, which is a common mistake in France ;

2- The centennial flood : A 100 year flood is a flood whose probability of occurrence over a year is of 1/100 chance , statistically it has 63% chance to happen in 100 years (see Fig.1) ;

3- The fifty-year flood :A50 year flood is a flood whose probability of occurrence over a year is of 1/50 chance, statistically it has 87 % chance to happen in 100 years (see Fig.2) ;

4- The ten-year flood :A 10 year flood is a flood whose probability of occurrence over a year is of 1/10 chance, they almost always happened. (see Fig.3)

3.3 Fig.1 Ile-de-France – Paris – Centennial flood – 2016

3.3 Fig.2 Ile-de-France – Villeneuve-Saint-Georges – fifty-year flood 2018

3.3 Fig.3 Ile-de-France – Draveil – ten-year flood - 2021

3.4 The historical 1910 flood damage and impact

The 1910 La Seine flood (8.60 meters) is the largest known overflow of La Seine after 1658 (8.96 meters). It affected most of its valley and caused significant damage to the regional economy. The flood occur in winter and the rise in water level took around ten days, and the fall in about 35 days. The suburban towns suffer significant damage too but at the time only 9000 inhabitants were living there and nobody paid too much attention to them. It’s until mid-March 1910 that the flood was completely absorbed. The flow was between 2,650 m3/s - 3,300 m3/s. La Seine's normal flow is around 500 m3/s (see chapter 3.3).

The impact and losses of the 1910 flood are important and the number of dead and injured weren't even estimated. What is known is :

- The flood caused an average of 7.5 billion euros ;

- 150 000 inhabitants suffered damage ;

- 20,000 buildings are flooded in Paris (see Fig.2) ;

- 30,000 houses were damaged in the suburbs (see Fig.1) ;

- 22,000 cellars and hundreds of streets are underwater (around 300 in Paris) ;

- Cars couldn’t travel in flood areas. Therefore, 75 000 horses were requisitioned for Paris ;

- Navigation on La Seine is stopped because there is no longer enough space to pass under the bridges ;

- The factory of the Urban Compressed Air Company is stopped, which stops public clocks, elevators, and electricity in Paris ;

- The health situation is worsening, cases of typhoid and scarlet fever are reported ;

- Subways and train lines / stations are closed ;

- Destruction or weakening of dikes that have been submerged and the price is high to repair them after ;

The 1910 flood left such an impact on the inhabitant mind that the actual region's official hazard flood map, the flood evacuation scenario (ORSEC) the anti-flood walls, and the maximum known level of flood in Ile-de-France (P.H.E.C.) are based on the 1910 flood impact.

3.4 Fig.2 Ile-de-France – Paris – Centennial flood – 1910

3.4 Fig.1 Ile-de-France

Villeneuve-Saint-Georges

Centennial flood - 1910

3.5 Hazard flood map

The flood hazard data is made both from past flood events – like the 1910 flood - and hydraulic engineering reports. Before 1932 only anecdotal maps reported floods event in France. In, 1932 is created the first national mandatory map production for the allregion. However, those first hazard flood maps were poorly applied, complex, and in conflict with the P.E.R. (foreseeable natural risk exposure plan - 1982). Considering that both these tools had the same objectives and that it was above all better to fight against urbanization in flood risk areas, a single document was created with a law of 1995 67 . The Plan for the prevention of foreseeable natural risks (PPRN) regroup all the natural hazard typeofplans andmap.For floodrisks, thesemapshave been calledPPRI (Flood Risk Prevention Plan).

67 la loi no 95-101 du 2 février 1995 relative au renforcement de la protection de l’environnement dite « loi Barnier »

3.5 Fig.1 -On top - Paris – Rare flood hazard data used in the region PPRI

3.5 Fig.2 Map of the 1910 flood in Paris

3.6 Modern flood impact and losses - 2016 Flood example

To illustrate the vulnerabilities of the region Ile-de-France the case of the 2016 flood come from an informative perspective.

The 2016 flood, a centennial flood, is the most impactful flood of the last 30 years in Ile-de-France. On the night of June 3 to 4, La Seine reached 6.1 meters in Paris. This level is the highest since 1982. Nevertheless, it remains much lower than the one recorded in 1910 when the water reached 8.62 m (see chapter 3.4). During the 2016 flood, huge material damage was recorded, the main cause of this river flood is due to rain events.

The main damages and losses during the 2016 flood are :

1- 4 people lost their lives ;

2- 24 others were heavily injured ;

3- Around 20,000 residents were evacuated ;

4- 25,000 properties were affected by these floods ;

5- In the center of Paris the flood forced some museums, shops and subway lines to temporarily close. Located near La Seine, Le Louvre and Orsay museums have been placed on red alert. They closed for 4 days.Art collections located in flood-prone areas have been moved to upper floors ;

6- 15,000 households were deprived of electricity ;

7- Road and rail traffic was severely disrupted. Several roads, including the A10 motorway, were closed for several days ;

8- River economical trade remained closed for several days too ;

9- Tourism was one of the most affected sectors by the flooding of La Seine : the Committee of River Shipowners (CAF) estimates the shortfall at 11 million USD for tourist transport companies on La Seine ;

10- Insurers have received 120,000 claims reports following the flooding on La Seine ;

11- Estimation by theAssociation Française de l'Assurance point the losses in a range of 900 million euros to 1.4 billion euros.68

Conclusion: The economic losses is higher than human causalities. Therefore, the built-environment is in the front line of flood losses.

68 Retour sur la crue de juin 2016 - EPI Seine - 24thAugust 2020

https://episeine.fr/actualite/retour-sur-la-crue-de-juin-2016 : visited on the 30th ofApril 2022

3.7 Ile-de-France flood risk protection

Floods were always a known event, even if they weren’t understood and /or controlled. However, devastating floods were often interpreted as divine punishment. The oldest engineering work in France and therefore the Ile-de-France region, on flood was found with theremains ofRomancities 69 Theideaoffloodas punishmentanddivine scourge seems to dominate the Middle Ages. There are few ways to protect from flood, except to obtain the clemency of heaven. Masses and processions are organized in honor of holy protectors of floods 70

It was not until the 18th century that a rational scientific approach to flood developed. To reduce the impact of major floods and protect people , agricultural and industrial activities, the region learned to innovate, seeks solutions, builds dams, levees, canals, etc. Furthermore, it obviously because of the industrial development during the 19th century that the use of the rivers and watercourses as a means of communication and theincreasing exploitationofwatercreatedadiversifiedformofactivitiesaroundwater. However, during the protection against natural risks was most often the responsibility of inhabitants or owners, generally grouped into associations 71 .

Followingasuccessionoffloodevents with disastrousconsequences in theearly2000s, the flood risk management diverged from a strict resistant strategy to a more resilient one.

Nowadays, the flood risk strategy in Ile-de-France use 5 type of protection :

69 Que faire des eaux d’inondation ? Le cas des villes de Gaule - CécileALLINNE - MCF, Université de Caen Normandie, Centre Michel de Boüard /CRAHAM – UMR-6273 - 16 octobre 2020

70 Les lendemains des catastrophes naturelles au Moyen Âge - Actes du 16ème colloque de la Villa Kérylos à Beaulieu-sur-Mer - Jacques Berlioz - Publications de l'Académie des Inscriptions et BellesLettres - 2006

71 Law of 16 September 1807 on the draining of marshes includes, following the debates, provisions on dikes still in force: "Article 33 - When it comes to building dykes at sea, or against navigable or nonnavigable rivers, streams and torrents, the need will be noted by the Government, and the expense borne by the protected properties, in the proportion their interest in the work; except in cases where the government thinks it useful and just to grant relief from public funds. It also granted associations a status giving them the possibility of mandatory interventions with, in return, increased control of their operation.”

1-

Located on the banks of the Seine, these walls maintained by the region district budget, it protect built-environments up to 7.32 meters in Paris but in the suburban area it’s from 30 cm to 2 meters maximum (see Fig.1 & 2 ).

Those protections were developed during the 20th century to reduce flood impact. They, nevertheless, have their limits, especially with the new vulnerably .

2-

Following the winter flood of 1910 and the 1924 flood in Ile-de-France, the French government and the Ile-de-France region decided to develop La Seine and its tributaries upstream to regulate the flow of the river. Thus, the Lac de Pannecière (see Fig.3), on theYonne, was the first reservoir lake named "Grand Lac de Seine" put into service during the year 1949. In 1966, it was the Lac d'Orient or the lake-reservoir Seine inaugurated. Then, in 1974 the lake of DerChantecoq, a lake-reservoir of the Marne river. It became the largest artificial lake in France. Between 1989 and 1990, it was the opening of theAmance lake and the Temple lake on the Aube river. A Fifth one is in construction and will soon be open.

According to a governmental study, the reservoir lakes would allow for a flood like the one of 1910 to reduce the water by 60 cm, which would have the financial consequence of reducing the amount of damage to 8.4 billion euros instead of the estimated 12.2 billion euros 72 During the June 2016 flood, they reached over 90% of their storage capacity. These basins can save a few centimetres but do not prevent all flooding and overflows.

TheAnti-flood walls :

3.7 Fig.1 & 2

Anti-flood walls

Choisy-le-Roi

2016 Flood

Reservoir lakes :

72 Rapport, Agence de l'Eau Seine-Normandie - 1992 à 1998, l'IIBRBS, en partenariat avec l'État, la région Île-de-France

In winter and spring (from November to June), the reservoirs' lakes are gradually filled, with canals or dams. At the time the rivers are at their highest. Additional samples are taken during periods of flooding to limit them. It’s named the “flood levelling”. From July to October the “low water level” takes place. When, during the summer, the rivers are at their lowest level, the water contained in the lakes is returned to them. The volume of each of the lake reservoirs depends on the importance of floods and droughts. As an example, in the event of drought in winter, thelakes may have to greatlyreducetheir contents, makinga compromisewith theneed to store water for the summer

Thereservoir lakes aren’t always considereda resilientstrategy.The flood returnperiod reduces year after year and the events occurring sooner than later, the reservoir lakes are sometimes flooding their surrounding. The new reservoir, La Bassée, is very controversial and some associations deplore the lack of vulnerability reduction and accuse the reservoir of only moving the risk to another area.

Unfortunately, the different alternatives do not make it possible to find equivalent effectiveness against floods, or present higher costs, without the possibility of phasing the operation. Therefore, the agricultural land is viewed by some populations as potentially sacrificed.

Located on the banks of La Seine, these pumps stations evacuate wastewater when La Seine is too high for conventional means to work, in particular avoiding the backflow of wastewater (see Fig.4).

3- Pumping stations :

3.7 Fig.4 Pumping station – Ile-de-Francce - Bougival-à-Louveciennes - 2019

3.7 Fig.3 Pannecière lake and its dam – 2008

4- Temporary protection

Temporary flood protection measures are one-time use protection only. It is put in place immediately before a flood to keep water out of a building for the duration and is removed after. These emergencies measures are sometimes called “active flood protection” because they require human intervention before a flood occurs. They are therefore only useful if there is sufficient warning time to allow the deployment of flood protection measures and if the building owner or another informed person is available to put the measures in place. It isn’t a permanent solution but only a temporary answer (see Fig.5)

5- Resilient strategy

Whiletheresilientstrategyhas now20yearsofexistencein theresearchand theofficial state flood risk management field in France, its impact on the built-environment is quite new. The first real adaptation from a resistant to resilient begin around the 2010s. In Ile-de-France, a resilient strategy aims to reduce flood vulnerability through the development of a sustainable built-environment. There is no real defined plans or list of what resilient protection should for the Ile-de-France scale (one for Paris itself exist) but 4 main points can be listed :

- Evaluate and reduce the vulnerability of goods, infrastructures and networks facing a major flood (1910 flood type) and its consequences on the territory ;

- Organizing crisis management and prepare for a return to normal ;

- Developing the risk culture of the entire population and of public and private

3.7 Fig.5 – Temporary protection named “batardeau” in French

actors ;

- Coping with risk for more resilient land use planning ;

To illustrate those points here some examples : raising streets levels, dwellings on the firstfloorwhilethegroundfloorletsthewaterpass, pathsallowingcirculationinheight, waterproofing, access at multiple levels, permeable pavement, water tank, elevating primary utilities (power, waste, water, etc.), use soft coastal engineering measures, use cellular waterbodies, bio breakwaters, floating homes , etc (see Fig 6 & 7)

3.7 Fig.6 – Permeable pavement

3.7 Fig.7 – Raised sidewalk level – Romorantin - 2018

3.8 Chapter conclusion

The region Ile-de-France is the most populated and dense in France (see chapter 3.1 Fig.5, Fig.4 &).Itis crossedbymanyrivers (see chapter3.1Fig.1).Itsmost emblematic one is the river La Seine which is also the most threatening when talking about flood in the region, but not in France. It travels from the south to the north of Ile-de-France and goes through Paris, then finishing its course to the sea (see 3.2 Fig.3 ). The region is divided into eight districts called "departement" and themself divided into sub-district called "commune" (see chapter 3.1 Fig.2 & Fig.3).

The main flood in this region is the river flood. The river flood danger is measured by its flow. La Seine flow is usually up to 500 meters cube per second but when it goes higher it means flood is happening. In French, for river flood we don't use the term "flood" - inondation - but "river in spate" -une crue-. La Seine' flood is slow, around 50cm per day, and has a natural flood system called the "return period". Four of them were determined, the 1/1000, 1/100, 1/50, and the 1/10 per year chance to happen.They are usually called the millenial, centennial, or fifty-year flood, which confuses many people to think those floods happen once every 1000/100/50/10 years. It is a common mistake in France when it actually means that each year, the probability that a flood occurs is of 1/xxxx chance (see chapter 3.3).

La Seine's floods are known for their power of destruction and danger. However, the most famous one is the 1910's flood. Even if worst flood happens since in terms of socioeconomic impact.At least the impactful memory of 1910's flood impacted the risk management in Ile-de-France, especially in and around Paris (see chapters 3.4 & 3.5). From 1910 to 2016 the flood impact on economic losses is higher than human causalities. Therefore, the built environment is on the front line of all flood losses in the region of Ile-de-France (see chapter 3.6).

Ile-de-France flood risk protection can be divided into five types : Anti-flood walls ; reservoir lakes ; pumping stations ; temporary protection & resilient strategy. The antiflood walls and the temporary protections are resistant strategies while the reservoir lakes and pumping stations could be considered resilient protection. However, those last two are integrated into the resistant strategy by their connection to the old risk management strategy even if they don't have a direct impact like the walls and dikes.

The resilient strategy in itself isn't defined in Ile-de-France. There is an intervention plan called ORSEC (Organisation de la réponse de sécurité civile / Organization of the

civil security response ) to help respond during the flood event but it only define the correct management of stakeholders like firemen, military, hospitals, etc. To determine if this management intervention is resilient or not isn't the subject of this master thesis and therefore can't be yet proved. Also, ORSEC isn't specific to floods. It could be an intervention plan on terrorism or industrial danger.

Paris does have a resilient plan. However, Paris isn't one of those master thesis cases and doesn't impact them, thus, it will not be discussed. From the old risk management strategy, only the reservoir lake could be considered as the first step of a resilient strategy.

In conclusion, the resilient strategy at the Ile-de-France scale isn't well defined and is only applied by architects often at its minimum to avoid cost orlocal inhabitants by mistake or lack of knowledge, because they don't know what flood resilient strategies are.

4.6.1 Introduction

CASE SELECTION

4.1 Introduction

4.2 Methodological steps

4.3 Selection of the second scale study area

4.4 Defining the communities

4.5 The two communities

4.6 Questionnaire data collection method

4.6.2 The questionnaire structure

4. CASE SELECTION

4.1 Introduction

The choice of a dual case studies analysis is based on the flood impact area in Ile-deFrance and the Covid-19 situation. With the pandemic difficulties, the easiest solution was to study the surroundings local area for the student (me) to be able to travel there without restrictions and study flood issue. Indeed, because of the random necessary Covid-19 curfew decision in the country - France - the case study was a city near the original student's university: Paris & its region, l’Ile-de-France.

The impact of floods and therefore the study of flood resilience is at stake in Ile-deFrance. Because of its economic, political, and cultural influence floods, the region is located in an important and vulnerable area.

4.2 Methodological steps

The previous steps, the Introduction (chapter 1), the Literature review (chapter 2) and the Local context (chapter 3) help to defined the frame, the research question, the scientific frame with the definition of resilience, what it is and what it isn't. How the previous floods impacted the risk management and what is considered a resilient builtenvironment in our local context.

The following step before the analysis of the case studies is to answer the first subquestion :

Which communities are more vulnerable and will be selected about as case studies?

This question will be answered with a territorial analysis, an on-site survey, through flood risk and existing vulnerabilities like social-economic weakness, builtenvironment issues, and the frequency of floods (see next Chapter 4.3).

The next step of this research, chapter 5, 6 & 7, will analyse 2 cases studies to answer the sub-questions :

- What is the type of flood resilient built environment in those communities ?

- What are the most important built environment factors to influence flood resilience ?

- Which one of those factors adds vulnerabilities or resiliencies and why?

Those questions will be answered during the analysis through the perspective of :

- The community summary: population, flood hazard plan, etc ;

- It’s historical background & past flood issues ;

- The local built environment and how resilient it is ;

- The personal on-site survey results ;

- The questionnaire results ;

- And the general outcomes of all those information.

Then, in the final step, chapter 8, will be answered the main question “How the influence of the built environment can improve communities to be more flood resilient ? “.

4.3 Selection of the second scale study area

The first scale study was the region Ile-de-France (see chapter 3.1). 32 communities in flood area were chosen as case studies to answer this master thesis question. To choose in those 32 communities which one to study the vulnerability of the Ile-de-France region was studied following by an information merging from the precedent chapter. It reduce the scale of the research to our second scale study.

From the chapters 3.4 & 3.6 (The historical 1910 flood damage and impact & the Modern flood impact and losses - 2016 Flood example ) the main losses and damages from a river La Seine flood in Ile-de-France since 1910 is the built environment and not the human casualty.

In the Local context chapter (chapter 3.1), was defined the region Ile-de-France and when looking into the map 3.1 Fig.4, Ile-de- France – Municipality Density Population per Km² and the 3.1 Fig.5, Ile-de-France – Land use, the most populated areas, and urban landis locatednear Paris.Thesurrounding region district is Hauts-de-Seine(92); Seine-Saint-Denis (93) ; Val-de-Marne (94) (see 3.1 Fig.2 :. Ile-de-France Region districts).

In chapter 3.2 - Ile-de-France region flood - the south territory of La Seine near Paris came up briefly. It was described as the first area to see the river La Seine flood happening because La Seine flow is coming from the South and end up in the North.

As the upstream of La Seine (La Seine amont territory : see the end of 3.2 chapter, Ilede-France region flood ) is the part of the territory with the most rivers connection, the flood hazard is larger. (see 3.2 Fig.3 Ile-de-France – Topography with flood hazard & La Seine flow ). In his thesis, Kenji Fujiki 73 evaluate the social and economic vulnerability of Ile-de-France. The largest area of social vulnerability is located upstream of La Seine in the Val-de-Marne district. (see Fig.2).

73 Prospective study of the social impacts of a major flood in the Ile-de-France region. Socio-spatial disparities in the care of Ile-de-France populations in crisis and post-crisis situations: a mapped and quantified analysis of household needs, from evacuation to reconstruction - Kenji Fujiki, Thesis , Geography. Université de Lyon (Université Jean Moulin Lyon 3), 2017.

The most vulnerable area in term of flood risk in the region Ile-de-France. There are 4 region districts : Paris, Haut-de-Seine, Val-de-Marne, Seine-Saint-Denis

Social vulnerability legend

Departemental limits Communal limits (TRI)

Very high

Upstream territory, region districts : Val-de-Marne & Essonne

Very weak

4.3 Fig.2 Social-economic vulnerability- Ile-de-France – Kenji Fujiki - 2017

4.4 Defining the communities

The region vulnerability analysis point to the center of Ile-de-France region. With the study of social-economic vulnerability (see 4.3 Fig.2 ) the most interesting area to look for cases studies seems to be in the South suburb of Paris : the Val-de-Marne district.

TheVal-de-Marnedistrict is dividedin sub-district ormunicipalitiesnamed “Commune” in French. Nineof those sub-district are near La Seine (see Fig.1).

All those 9 sub-districts have a part of their territory in flood hazard areas. For some of them – in the red flood hazard zone - La Seine rise with a “return period” (chapter 3.3 La Seine flood fluctuation)of 2to10years(see Fig.2).Intheseneighborhoods,resilient flood risk management is an essential strategy for the protection of both builtenvironment and human lives. Two of these neighborhoods in particular are experiencing an increasing number of flood (see Fig.3).

4.4 Fig.1 Val-de-Marne -9 Sub-districts near La Seine

Most common hazard areas and therefore where there is the most flooded areas every 10 years.

4.4 Fig.2 Val-de-Marne -9 Sub-districts near La Seine – Flood hazard map

4.4 Fig.3 - 2 Neighborhoods– Flood hazard map

The 2 neighborhoods /

4.5 The two communities

There are several neighborhoods flooded every 2 to 10 years. The communities living there are the most endangered and that’s why they were chosen for this study. However, other criteria should be taken into account :

1-The communities are around La Seine only, because our subject is La Seine’s floods ;

2-Ithas to beareas where peopleareliving (sotherecan bea questionnaireandanswers from local inhabitants) ;

3- Strong communities, where people recognised themselves through a specific name and specific limits to do an accurate on-site survey.

With those criteria, the two neighborhoods / communities chosen are :

1- Le Port Neighborhood (Choisy-le-Roi sub-district)

4.5 Fig.1 – Le Port Neighborhood

Choisy-le-Roi – Google earth - 2022

2- Triage Neighborhood (Villeneuve-Saint-Georges sub-district)

4.5 Fig.2

Triage Neighborhood – Villeneuve-Saint-Georges – Google earth - 2022

4.6 Questionnaire data collection method

4.6.1 Introduction

Because resilience and town planning is a part of the territory as perceived by everyone, the questionnaire solicited the inhabitants' view on the matter.

The scientific and societal objective of this master thesis on flood resilience is to bring together a technical approach to town planning that are scientific/architectural maps and the citizens' local perspective of resilience. Representation through a more local point of view gives this master thesis more structuring elements to answer its question : How the influence of built environment can impact community flood resilience . The questionnaire concern different positive and negative aspects of local resilience and then a more defensive aspects such as flooding and therefore the notions of risks, vulnerabilities, and resilience.

This master thesis has the will of given a diagnosis made of shared challenges from both the town planners and the citizens.

1/ allow citizen to explain their point of view, compare those points of view and add their knowledge and visions,

2/ allow the master thesis to acquire sensitive knowledge,

3/ to advance research by crossing and synergizing technical points of view (research) and citizen visions.

4/analyze the flood risk cultures of citizens subject to evacuation, as was the case in Villeneuve Saint Georges in January 2018.

The questionnaire favors an intensive approach, delving into a limited number of cases. This master thesis questionnaire is made of semi-structured interviews with mostly open-ended questions. The main function of this research questionnaire is to broaden the scope of the survey and to verify statistically if the information and hypotheses constituted can be generalized. Its structure is strongly conditioned by the objectives and constraints of the research questions. Intended for statistical processing, the questionnaire must be pre-constructed. Unlike the semi-structured interview, it asks everyone the same questions formulated in the same terms and presented in the same order. Only the answers are different.

The questionnaire was first made in French and then translate into English to be able to analyze the results and share them through this master thesis. The answers were manually collected and an excel version with the answers was made to compare them. The examples of the questionnaires can be found in the appendix chapter.

The questionnaire was answered in person in the street with the local inhabitant of each community.An online questionnaire was an option but the inhabitants of the case study wouldn’t seem to respond favorably to it.The reasons are multiple : Old population and lack of understanding for phone / computer use. Migrants population with language and reading difficulties. Flood victims are less prone to share information by themselves about their situation, shamed of being low-income population. Difficulties to push the understanding of a questionnaire used on that subject reducing the number of potential respondents.

Therefore, it was determined that flooded communities in the south of Paris would be more responsive to a face to face questionnaire.

It also ease the answer to some questions because the inhabitants don’t always understand specific words and needs term specifications and definition

Sometimes people working or coming often into the neighborhood were interrogated too, but only the inhabitant's answers were kept.

A total of 53 people were questioned. 20 in Le Port Neighborhood and 23 in Triage neighborhood. The questionnaire happened :

- In Le Port Neighborhood : on Saturday 26th of March and the 24th and 25th of May 2022, at the local outside market and at Le Port neighborhood next to La Seine.

- In Triage Neighborhood : on Saturdays 2, Sunday 3April and the 25th and 26th of May 2022, in Triage’s streets

4.6.2 The questionnaire structure

The constraints of this questionnaire are this master thesis questions :

- What type of flood resilient built environment is in those communities?

- What are the most important built environment factors to influence flood

resilience?

- Which one of those factors adds vulnerabilities or resiliencies and why?

It’s objectives is to makes it possible to identify the typical profiles of people living in a flood-prone municipality. It also has the objective of identifying the existing resilient built environment and how the population are living with it. This aims to lead to improvement and to follow the evolution of the perception of flood risk management in the communities. The questionnaire also has the advantage of giving communities the opportunity to express themselves directly.

To establish the frame of the questions, the questionnaire is divided in 4 categories including a total of 21 questions :

1- Basic observation and questions

The first category is the basic information about the respondents : Gender, age and occupation. They can be found on the top of the Excel file with the participant number. The gender is divided in two answers :

1.1- Male

1.2- Female

The age is divided in five part because some people refused to answer a precise number. To avoid reluctance a scaled question was proposed :

1.3- 15 to 29 years old

1.4- 30 to 44 years old

1.5- 45 to 59 years old

1.6- 60 to 74 years old

1.7- 75 and over years old

The occupation question, is divided in three answers :

1.8- Employees

1.9- Retired

1.10- Unemployed

2- The inhabitant's living location and condition

The built environment is often narrowed down to only the living spaces. However, mobility is a very important part of the built environment in flood areas. The impact

of floods on mobility is more prominent and heterogeneous. It could both isolate the inhabitant from both an evacuation and the important day-to-day life travels. On the indirect aspect of the damages, the impact of floods on mobility built environment can block the circulation in the long term. Destroying streets, bridges, roads, pedestrian paths, and any valuable access. During the flood, it also pushes the inhabitants to create their own mobility, sometimes very dangerous.

Four questions are related to this category :

2.1- Do you live on the banks of La Seine ?

2.2- Do you live in a flood zone ?

2.3- Do you work in a flood zone ?

2.4- What is the typology of the building which you live in ?

3- The mobility

The built environment if often narrow it down to only the living spaces. However, the mobility is a very important part of the built environment in flood areas. The impact of floods on mobility is more prominent and heterogeneous. It could both isolate the inhabitant from both an evacuation and the important day to day life travels. On the indirect aspect of the damages, the impact of floods on mobility built environment can block the circulation on the long term. Destroying streets, bridges, roads, pedestrian paths and any valuable access. During the flood it also push the inhabitants to create their own mobility, sometimes very dangerous one

Two questions are focused on mobility :

3.1- What type of mobility do you use the most ?

3.2- Where do you often travel in your community ?

4- Flood events & protection resilience

The fourth and last part is made of questions on the flood events and therefore the flood areas. They ask what is the flood areas for the inhabitant; if they know them; if they live in one; if they already had to live through a flood; if yes, did they change something afterward in their built environment, and mostly what happen during and after the flood event(s). Four questions are also related to the flood protection ; if they know them and if they appreciate the existing resilient

protection. The goal of those questions is to directly answers the questions surrounding resilience and flood.

4.1- What are the flood zones for you?

4.2- Do you find that the flood protections are effective?

4.3- Which type of flood protection do you think is the best ?

4.4- Which type of flood resilient protection do you prefer ?

4.5- Did you had a flood since you live in the community ?

4.6- Was your living space flooded ?

4.7- Did you change (on your built-environment) anything after that flood ?

4.7.1- If yes what ?

4.8- Did you had life safety problems during or after flood ?

4.9- Did you need food during food if yes how did you get it ?

4.10- What bothered you the most during the flood ?

4.11- Did you had to move from your home ?

4.11.1- If yes where ?

LE PORT NEIGHBORHOOD

5.1 Introduction

5.2 Le Port Neighborhood important location

5.3 Historical background

5.4 Density : FAR

5.5 Flood History & Flood Hazard

5.6 Resilient built environment

5.7 Questionnaire results

5.7.1 Responders’ gender / age & occupation

5.7.2 Inhabitant's living location and condition

5.7 3 Mobility

5.7.4 Flood & Protection

5. LE PORT NEIGHBORHOOD

5.1 Introduction

Le Port neighborhood is located south, near La Seine in the district Val-de-Marne, in the sub-district of Choisy-le-Roi. Since 2000, many developments were made in Le Port neighborhood. Nowadays, it’s almost completely rebuilt. It is now a modern and pretty architectural space. The banks of La Seine and the forecourt is home to many eventsincludingtheChoisyfestivals.Thetrainstation,justbehind,hasopenedasecond access for reduced mobility people. There are two office buildings, one which is occupied by a hospital structures and a private crèche as well as a hotel and a student residence. However, thereis stilllandonwhichprojects must becreate.Therefore,there are some large empty wilderness areas. Just in front of La Seine, there is a large library, a basketball court and several modern apartments. In the surrounding can be found a house for associations meetings, a kindergarten and a gymnasium. La Port neighborhood is a village within the city with a total of 3000 inhabitants.

5.1 Fig. 1 - Le Port Neighborhood – google earth - 2022

The most important and recognizable areas in Le Port neighborhood are located at the front riverside. The composition is a variety of private buildings, public facilities, an empty wilderness zone, and a large riverbank area with still one industrial activity, the last one of a long industrial past. The area represents 74 600 m². The mobility built environment represents 22 802 m² (streets and paths) and the 4 blocks composing the rest (buildings, park) represent 51 798 m².

5.2 Fig. 1 - Le Port Neighborhood important location 2022

N°2- Fig.3 : River Bank

N°1- Fig.2 : Empty wilderness areas

N°4- Fig.4 : Library

N°5- Fig.6 : Park

N°3- Fig.5 : Parking

N°6- Fig.7 : Dwellings

5.3 Historical background

“Le Port” means “harbour”, therefore “Le Port neighborhood” is named after the old previous harbour. The history of Le Port neighborhood is linked to its sub-district Choisy-le-Roi. It is difficult to trace its history before the arrival of the King of France in the 18th century. The oldest traces of human presence date back to 5000 years ago. In the Middle Ages, Choisy with its harbour, was a small village with a few houses of fishermenandsailors.In 1207,theinhabitantsbuiltachurchdedicatedto Saint-Nicolas, whoistheguardianofsailors.Theportis,atthetime,thefirstpecuniaryandsubsistence resource. Thus, La Seine has always influenced the place, and the King made the harbour a supply base for Versailles. Benefiting from this impetus, trade, and craftsmanship led to the establishment of the first factories.

In the middle of the 19th century, the railroad rapidly extended from Paris to the train station behind Le Port neighborhood. In the 1970s, the progressive deindustrialization transformed the surroundings of the harbour into abandoned areas, although some companies are still there like a Sands and Gravels business. However, the activity is no longer what it used to be. To reconcile a growing population and the harbour activity, from 2014 to 2017, a redevelopment project transformed the face of the neighborhood.

5.3 Fig. 1 - 1756

5.3 Fig. 3 - 1950

5.3 Fig. 4 - 2022

5.3 Fig. 2 - 1866

5.4 Density : FAR

From 2000 to 2017 the neighborhood face is transformed gradually from a postindustrial harbour to a mixt used place with both a small remain of the past industry and the new urban area. Consequently, its built density is higher. The neighborhood got used to urban environments with higher densities and a new community. It has all kinds of advantages : the immediate benefits include better public transport, a higher level of amenities, and proximity to a dynamic economic environment that generates jobs for the local population. However, higher density also prevents the occupation of green spaces and unnecessarily long commuting times for people housed even further away from the city. Which can both play an important role in flood resilience (impermeable pavement) and flood evacuation (less evacuation access). Thus, the FAR of this neighborhood will be exposed and compared to the two other communities to see if a densely built environment adds vulnerability or can create an opportunity for flood resilience.

Le Port neighborhood is divided into 4 blocks composed of buildings, parks, etc. Its surface represents 51 790 m². The neighborhood has a low / middle-density area compared to its previous one, the old industrial harbour, which was even lower. That result was predictable knowing the new built environment was made to accommodate a rising population in the sub-district, from 11 607 inhabitants (in 1910) to 45 331 (in 2017).

(As a reminder : the Floor area ratio (FAR) is the measurement of a building's flood area concerning the size of the lot/parcel that the building is located on. FAR is expressed as the building area divided by the lot area.)

5.4 Fig. 1 – F.A.R. map

5.5 Flood history & Flood hazard

Close to La Seine, Le Port neighborhood lived through many floods. The flood in the neighborhood can reach 2 meters and block streets. It is also likely to last from several weeks to several months and mostly in summer or winter, like in 1910 (see Fig.1). Le Port neighborhood was impacted by every important flood of the last century : 1910, 1924, 1955, 1982 and 1999 / 2000s, 2016, 2018. Nowadays, the flood hazard map of the neighborhood still shows the full area in high flood hazard or at least medium flood hazard (see Fig.7 at the end). The sub-district, in their mandatory flood protection map (see Fig.3 just below) classifies the neighborhood as a “dense urban area with strong and very strong hazards”

5.5 Fig.1 - 1910 flood on the train rail behind Le Port neighborhood

5.5 Fig.2 Flood protection map : PPRI

The last most important flood in Ile-de-France, in the past 10 years, and therefore in the community Le Port neighborhood, occurred in 2016, 2018 and 2021. Which is perfect because it will give us the opportunity to analyse the impact of the resilient built environment and to regroup those information with the questionnaire of the community later.

The most damaging of those 3 floods are the 2016 & the 2018. 15 000 m² of the built environment (21%) and 6000 m² of mobility area – streets and roads - (26%) were flooded during the 2016 & 2018 events. Four of the important riverbank location in the neighbourhood were flooded and closed for several weeks / months after.

5.5 Fig.4 – Beginning of the 2018 flood in the parking

River Bank Parking

5.5 Fig.5 – Street & library flooded 2016

5.5 Fig.6 – Park flooded 2018

5.5 Fig.3 – River bank flooded 2018

5.5 Fig.7 – Flood Hazard map

5.6 Resilient built environment

Intheearly2000s the regionIle-de-Francedecided on themainpoint of aresilient flood strategy :

- Evaluate and reduce the vulnerability of goods, infrastructures and networks facing a major flood (1910 flood type) and its consequences on the territory ;

- Organizing crisis management and prepare for a return to normal ;

- Developing the risk culture of the entire population and of public and private actors ;

- Coping with risk for more resilient land use planning ;

In the following years, the protective flood plan (PPRI , see 5.5 Fig. 3 - Mandatory flood protection map – PPRI ) framed the flood protection with several urban rules and planning. Therefore, at the same time in the sub-district Choisy-le-Roi, the municipal council approved a new construction plan for Le Port neighborhood The area development planning had to allow the banks of the Seine to be reconquered. The program includes 870 housing units, 3,300 m2 of public facilities like a nursery school, agymnasiumandacommunitycenter,2,000m2 ofshopsonthegroundfloor,and4,500 m2 of offices and activities.An urban boulevard between La Seine and the railway line opened up the district which, when it was an harbour was isolated from the rest of the sub-district.

Then in 2014 the new project development aimed to ensure the requalification and openingupofwhatwasseenasadeprivedneighborhood.Mainlyoccupiedbyindustrial activities unsuited to flooding. The new development of Le Port also aims to promote the appropriation by the inhabitants of the banks of the Seine.

A list of the resilient built environment is described on the next page. Some of those built environment are outside the neighborhood perimeters because their influence are strong on the community resilience. Thus, they can’t be ignored and were added.

5.6 Fig.1 Le Port neighborhood resilient built environment – google earth - 2022

N° 1 - Fig 2 - Dwellings on the first floor

N° 2 - Fig 3 - Creation of a large park to leave more place for rainfall absorption

N°3 - Fig 4 - 50% permeable pavement

N° 4 - Fig 5 - Construction on stilts

N°5 - Fig.6 - New rainwater drainage system

N°7 - Fig.8 - Gardens

N°6 - Fig.7 - Redevelopment of the old port on the riverbank

N°8 - Fig.9 - Creation of two bridges to connect the neighborhood to the rest of the city

N°9 - Fig.10 - Raised road access

N°10 - Fig.11 - Flood mark as historical witnesses of flood memory

N°11 - Fig.12 - In front of Le Port : Redevelopment of the banks

5.7 Questionnaire results

Of all the 53 inhabitants interrogated, 27 are from Le Port neighborhood community. They were interviewed near the local outside market and in Le Port neighborhood next to La Seine. The general results from Le Port neighborhood are divided into 3 axes :

1- The responders’gender / age & occupation

2- The inhabitant’s living condition

3- Their mobility

4- The flood events & the flood protection

5.7.1 Responders’gender / age & occupation

The respondents are divided between men and women with an average percentage for both but still a bit more for women (+4% see 8.1.1 Table/Diagram n°2 : Respondents gender – Chapter 8.1). The respondents are aged from 15 to 75 and more. Most answers are coming from inhabitants aged between 45 to 59 years old (41% see chapter 8.1.1 Table/Diagram n° 2 : Respondents age). A large part of the respondents are employed (48%), few are unemployed (8%) and the last 44% is divided between students (22%) and retired population (22%) (see chapter 8.1.1 Table/Diagram n° 4). The community is active The majority are couple with one or two kids. Their incomes seems more stable than the next case study.

5.7Fig.1 Questionnaire area map

5.7.2 Inhabitant's living location and condition

All the inhabitants questioned in Le Port neighborhood considered themselves living on thebank ofLa Seine (seechapter 8.1.2Table/Diagram n° 5).This could beexplained with theriverbank redevelopment andthearchitectureofLePortneighborhood.Indeed, almost all buildings have a view on La Seine (see 5.7.2 Fig.1).

Even ifthis pre-construction schemawasn’t followed foreverybuilding, theideastayed as a strong design recommendation by both the local political administration and the different architects working on site. Let’s not forget that the view on La Seine rise also the price of each flat.

The respondents all live in a flood area but half of them of them aren't aware of this important fact (see chapter 8.1.2 Table/Diagram n° 6). None of them are working in a flood area, or at least they don't know about it (see chapter 8.1.2 Table/Diagram n° 7). The density of this young neighborhood has only middle-rise buildings. Thus, every inhabitant is living in one of those middle modern high buildings (see chapter 8.1.2 Table/Diagram n° 8). Because of this density, the vulnerability of the neighborhood could be understood as rising. However, we will see that density doesn’t always mean vulnerability on flood subject.

5.7.2 Fig.1- Architecture schema ideas on Le Port – mainly view on La Seine - 2006

unobstructed views of the seine

Free spaces clear of the ground Railway

unobstructed views of the seine

Acoustic ramparts - to reduce the noise of railway tracks

Building R7

5.7.3 Mobility

The occurrence of disruptions in the mobility built environment from flooding impacts changes the spatial distribution of traffic load within the road network and the speed at which its users can travel therein. Furthermore, it creates, in opposition to the flood, an evacuation map (see 5.7.3 Fig.1 below).

When looking at the mobility-related to flood and resilience, the analysis often shows the need to change the existing built environment to increase the community resilience, especially for evacuation. However, the actual community accessibility is good enough to allow a quick and clear evacuation during a common flood, even if the road on the riverbank is always flooded. No matter how much this road is blocked, the sideways are numerous and allow evacuation, expect, maybe, during the rare hazard flood (see 5.3 Fig.2 Flood Hazard map). Thus, when considering only the common flood, 80% of the mobility connecting the community to the rest of the territory remain accessible. Therefore, the community never had to evacuate and the living condition are always maintained so far unless the flood rises to the rare hazard one day (see 5.3 Fig.2 – Flood Hazard map). In the questionnaire the inhabitants indicates a large type of mobility use (see chapter 8.1.3 Table/Diagram n° 9) :

1- Car (29%)

2- Bike (13%)

3- Public transport (38%)

4- Pedestrian (20%)

5.7.2 Fig.1 Flood evacuation main access

The community inhabitants travel mostly to the supermarket. Otherwise, the most visited space in the community is the bakery (14%), the library (8%), and the park (8%) and the Bar tabac (10%) (see chapter 8.1.3 Table/Diagram n° 10) . While the bakery and the bar, never suffered a flood yet, the library and the park, however, are the usual flooded areas (see chapter 5.5 Flood history & Flood hazard). The library and park structure don’t suffer from the flood. However, the community always deplored their closure during and after the flood (see chapter 8.1.4 Table/Diagram n° 20).

Some inhabitants vision of the community is larger than their neighborhood and the flood area. Indeed, when asked "where do you often travel in your community?" the inhabitant sometimes describes outside areas (“outside neighborhood” answer see chapter 8.1.3 Table/Diagram n° 10 ) The reason for this larger view is directly related to the new bridges and access made to open up the neighborhood over the past 20 years. It allows both the outsiders and the local community to use the riverbank space together. Therefore the flood events and flood risk management is known by other populations.

The car and public transport are the most used mobility by the responders (see chapter 8.1.3 Table/Diagram n° 9). Accordingly, when a flood occurs, streets are blocked, the local parking is flooded and the community worries about the car parking space (48%) (see chapter 8.1.4 Table/Diagram n° 20). To ease the situation, the sub-district authorities always allows the community to park in some -usually- illegal areas during and after the flood until the water leave and the streets are cleaned.

5.7.4 Flood & Protection

The inhabitants see flood as a curiosity. Some of them even talked about the animals coming further into the neighborhood because of the water rising event. Otherwise, there is no real recognition of the flood zone (the flood zones is "where there is water sometimes" –37%seechapter8.1.4Table/diagram n°11).However, most ofthem (45%) acknowledge the danger of flood but only on other riverbanks, not their own (see chapter 8.1.4 Table/diagram n°11). It does make sense because the riverbanks in front of them are also in an important flood area and only protected by a 2 meters floodwall -a resistant strategy- except on the main street which always gets flooded at the same timeastheLePortneighborhood.Therefore,thecommunitydoesn'tevaluatethedanger of flood through their own neighborhood but with the damages from others. As a result, 48% of the respondents find the flood protections effective. The flood protection received a positive answer from the community even if 19% of the

responders doesn't seem to know what kind of flood protection there is in the neighborhood and 33% don’t think the protection are effective (see chapter 8.1.4 Table/Diagram n° 12). However - and surprisingly- the best type of flood protection for therespondersis floodwalls(35%) anddikes(13%),eveniftheirneighborhooddoesn't have any. Once again, the reason is probably the next neighborhood on the other riverbank use floodwalls. 29% of the inhabitants interrogated don’t even have a point of view on flood protection (see chapter 8.1.4 Table/Diagram n° 13).

Only10%answeredwith aresilienceprotectiontypebutwhenaskwhattypeofresilient protection they prefer, half of them acknowledge the riverbank redevelopment (see chapter 8.1.4 Table/Diagram n° 13).

The 13 % about the reservoir lake give the same answer when asking about resilient flood protection. However, we saw in chapter 3.7 that reservoir lakes aren’t always considered resilient flood protection. The sub-district organizing a lot of event on the new riverbank, the answer only demonstrate which flood resilience built environment the community is using the most.

Many respondents in Le Port community had lived through a flood in the neighborhood but none had their living space flooded (see chapter 8.1.4 Table/diagram n°15 & 16). None changed their built environment or felt a safety risk during the flood event. Food wasn’t an issue either. Probably because of the multiple mobility access (see chapter 8.1.4 Table/diagram n°17, 18 & 19) even if the main streets access near La Seine was deplored by 26% of them ( (see chapter 8.1.4 Table/diagram n°20). No one in the responders had to move from their home (see chapter 8.1.4 Table/diagram n°21).

Le Port neighborhood community flood resilience is quite high and very effective in common hazard floods. However, there seems to be a miscommunication on the resilient built environment itself. 62% of the responders don't know or don’t have an idea of what resilient flood protection is or could be (see chapter 8.1.4 Table/diagram n°14).

TRIAGE NEIGHBORHOOD

6.3

6.4

6.6

6. TRIAGE NEIGHBORHOOD

6.1 Introduction

Triage neighborhood is a community in the sub-district (municipality) of VilleneuveSaint-Georges. Its administrative limits are next to Choisy-le-Roi and 15 mins bus travel from Le Port neighborhood. Triage neighborhood is a low-income area with public housing and tiny pavilions. It is the home of 2,173 inhabitants who have an average age of 35 years old. Most are single people and mainly are tenants of their accommodation, even in a pavilion, which is usually owned by the inhabitant in this district. The neighborhood has various services and infrastructures but everything feels suspendedandsometimesabandoned.Severalhousesandflats areclosedandthepublic services are difficult to maintain, except for kid's school. All the neighborhood is blocked between La Seine and the national railway company (The S.N.C.F.). It’s completely disconnected from the rest of the territory and its sub-district.

6.1 Fig. 1 - Triage Neighborhood – google earth - 2022

6.2 Triage Neighborhood important location

Triage neighborhood is composed of several important and recognizable areas for its community. The neighborhood is near La Seine and most of its important locations are located at the front riverside. The composition is a variety of public facilities, public houses, and an empty wilderness zone, which is in construction for new private buildings like in Le Port neighborhood. The area represents 286 400 m². The mobility built environment represents 27 500 m² (streets and paths) and the 4 blocks composing the rest (buildings, park) represent 258 900 m².

6.2 Fig. 1 - Triage Neighborhood important location 2022

N° 1 - Fig 2 – Old destroyed industry area

N° 2 - Fig 3 – River path

N° 3 - Fig 4 –Sport field

N° 4 - Fig 5 - Supermarket

N° 5 - Fig 6 – Only local street with many small business (pharmacy, restaurants, convenience store, etc)

N° 6 - Fig 7 – Private harbor

N° 7 - Fig 8 – Guinguette, typical river restaurant

N° 8 - Fig 9 – Train station

N° 9 - Fig 10 – Pétanque sport field

N° 10 - Fig 11 – Elementary school divided in two parts

6.3 Historical background

Triage” means “sorting”. Triage neighborhood was named after the switchyard / marshalling yard surrounding and isolating it. Before the 19th century, the place was only occupied by forests, fields, and wine fields. In 1847, after 4 years of construction, the Paris-Lyon train line was opened and this changed the relationship between the banks of La Seine into an industrial occupation. This arrival of the railroad created in its wake the Triage neighborhood.At the time, the community was mainly made up of workers from the national French railway company. The neighborhood then develops according to the life of the workers of the railways and the boats who could, before its destruction in the middle of the 20th century, deposit their goods inside the neighborhood. In 1882, the wagon manufacturing workshops moved from Paris to Triage neighborhood. The site behind the community included then, manufacturing, repairs, and a train yard, with 15 different tracks. The area employed approximately 2,500 workers who almost all live in Triage neighborhood.

6 3 Fig. 1 - Triage Neighborhood - 2016 photo

In 2006, the activity drop led to the closure of the marshaling yard. The remains are only some maintenance workshops.This industrial activity was for more than 100 years one of the most important centers of the Ile-de-France railway junction. Following the closure of the sorting activity, its facilities are now partly fallow. Consequently, Triage neighborhood community is slowly replaced by a new type of population, still low income, but living there because it's cheaper, not because they are related to the industrial / worker world nearby.

6.3 Fig. 2 - 1756

6.3 Fig.4 - 1950

6.3 Fig. 5 - 2022

6.3 Fig. 3 - 1866

Triage Neighborhood

6.4 Density : FAR

Triage neighborhood never really changed in 60 years, and is now composed of 16 blocks. Those blocks represent 258 900 m². Some buildings from 1930 are still used and 30% of the community are living in old public houses built at the beginning of the 20th century The only new urban fabric is located in the higher density : the FAR 2 block. Furthermore, the density is very low and is a good representation of the pavilions and public houses that composed 70% of the neighborhood.

6.4 Fig. 1

F.A.R. map

6.5 Flood history & Flood hazard

Triage neighborhood, next to La Seine, suffered many floods. The flood in the neighborhood can reach 2 meters and block all the streets Like Le Port neighborhood, the floods can last from several weeks to several months and mostly in summer or winter. The community experience with the 1910 flood is similar to Le Port neighborhood (see Fig.1). The community of Triage neighborhood still suffer from flood nowadays the same way it did 60 years ago, nothing changed. Furthermore, the flood hazard map of the neighborhood from the sub-district, only shows the level water can reach (see Fig.2). The sub-district, in their mandatory flood protection map doesn’t show any vulnerability or other important information (return period, flood hazard, etc.) The national data for flood hazard has a better representation of what flood looks like those days than the sub-district mandatory flood protection map .

6.5 Fig.2 Flood protection map : PPRI

6.5 Fig.1 – Triage flood 1910

During the 1910 flood, 100% of the community was flooded. Nowadays, with a typical common flood, Triage neighborhood is already flooded around 60%, as in 2016 and 2018.

The damages of a common flood is usually impacting 132 230 m² of the community built environment (46%) and 19 200 m² of mobility area – streets and roads - (7%). Seven of the important riverbank location in the neighborhood are always damaged and/or closed for several weeks / months after a common flood.

Guinguette 2022

6.5 Fig.3 – Guinguette flooded 2016

Main street 2022

6.5 Fig.5 – Main street flooded 2016

Pétanque strip 2022

6.5 Fig.4 – Pétanque strip flooded 2016

6.5 Fig.6 – Train station 2018 Train station 2017

5 Fig.7 – Flood Hazard map

6.6 Resilient built environment

In 2013 was launched a project development in Triage neighborhood. The first new built environment was done between 2013 and 2014. The will of the city councillors was to create in Triage neighborhood the conditions for sustainable urban development around La Seine. This work aims to preserve and enhance the ecological value of the banks and to create a large cycle path. The construction will last for about fifteen years (2028). It is supposed to quickly make it possible to facilitate soft traffic, improve the presence of nature in the community, and also to renew the leisure area the neighborhood can offer. The riverbank project part is already finished and had already three common floods plus some minor rising water events.

During the same year, 2013, another project launched by the mayor of the sub-district, aimed to revitalizethedistrict whilekeeping its villagespirit,including theconstruction of shops and numerous public spaces, nearly 800 housing units, and business premises forsmall andmedium-sizedenterprises. It also includes local publicfacilitiesto support the arrival of new families. While made of good ideas, the project doesn’t connect with the flood/risk culture of the first project. Floods are never approached in the planning and the rare resilience built environment modifications are only restricted by the region andsub-regionrules,whichisn’t enough.LaSeine floodcultureseems tobe completely forgotten and this omission only adds vulnerability to the actual and future community.

Besides, the only real new construction of a resilient built environment - the riverbankwas never finished as the architects presented it at first, many damaged elements weren’t repaired after the 2016 flood and the few restitutions are using non-resilient material (see Fig.)

Worse, the second part of the only school on the riverbank, (school divided into two parts, see n°10 on chapter 6.2 Fig. 11), was not included in the development project but it’s safer part near a dike will be rebuilt almost completely. The new school project is part of an eco-responsible approach. The new building was designed to reduce its energy bill and its carbon footprint While it is a good evolution for the school, the priority in a community flooded every 2 to 10 years should be the flood resilience management and not adding vulnerability to the community. However, after analyzing the past, recent and future built environment in the community, the past one seems to already carry a resilient strategy. Indeed, the pavilion and the old social housing are built higher or out of the common flood area (see chapter 6.6.2).

6.6.1 Recent resilience

The major recent resilient built environment is located on the riverbank of the neighborhood. It’s mostly made of private gardens, permeable pavement and a nonvulnerable activity use of the space like sports facilities. However, some damages made by floods were repaired with non-resilient materials and with the 2016, 2018 and 2021 floods, the damages doesn’t seems to be really flattering on the effectiveness of the new resilient built environment.

6.6.1 Fig. 1 – Permeable path

6.6.1 Fig. 2 – Sport facilities

6.6.1 Fig. 3 – Private gardens

6.6.1 Fig. 1.2 –Permeable path rebuilt after flood with concrete (not resilient material)

6.6.2 Past resilience

InTriageneighborhoodtheexistingmobilitybuiltenvironmentandthedrainagesystem aren’t resilient and suffer at every flood event (see Fig.2). Yet, when looking at some parts ofthepast built environment thecommunityseems to alreadyhavearesilientbuilt environment like : living spaces on higher ground (see Fig.3) , a permeable path near La Seine (see Fig.5), and raised gardens / landscape (see Fig.4).

Dwellings

Permeable path near La Seine

«

6.6.2 Fig.1 Triage neighborhood resilient built environment section

Fig.2 Streets and drainage system not resilient

N°4 - Fig.3

living space built on the first flood. Ground flood : only garden & garage

N°5 - Fig.4 Raised landscape

N°6 - Fig.5

chemin de halage », ancient hauling path.

6.7 Questionnaire results

Of all the 53 inhabitants interrogated, 23 are from Triage neighborhood community. They were interviewed on the riverbank path and the main street of the neighborhood :Avenue de Choisy. The general results from Triage neighborhood are divided into 4 axes :

5- The responders’gender / age & occupation

6- The inhabitant’s living condition

7- Their mobility

8- The flood events & the flood protection

6.7.1 Responders’gender / age & occupation

The respondents are divided between men and women with an average percentage for both but still a bit more for women (+4% see 8.2.1 Table/Diagram n°2 : Respondents gender – Chapter 8.2) which is the same than for the precedent case study in Le Port.

The respondents are aged from 15 to 75 and more. Most answers are coming from inhabitants aged between 30 to 44 years old (35% see 8.2.1 Table/Diagram n° 1 : Respondents age – Chapter 8.2). It's not surprising knowing that the French national institute gives the inhabitants' average age in this area as 34 years old 75.Alarge part of the respondents are employed but the other majority are unemployed. In 2018 already the French national institute determined that the poverty rate had raised to 35.7 % . The average income of a resident is €13,901 per year, which is very poor (ref). It is below the national average : €20,590 per year .

6.7.2 Inhabitant's living location and condition

In Triage neighborhood only half of the inhabitants questioned considered themselves living on the bank of La Seine (see 8.2.2Table/diagram n°5) but the majorityknow they are in a flood area (see 8.2.2 Table/diagram n°6). However, none of them are working in a flood area (see 8.2.2 Table/diagram n°7), or at least they don't know about it. The diversity of dwelling typology in Triage neighborhood is obvious when visiting the site and even more when asking where people are living. The average density is low and more than half of the community lives in a pavilion. It doesn’t mean they own the house or that there are living alone. Indeed, most of the inhabitants of Triage rent their dwelling and share it with flatmates or close neighbours, even the pavilion one. Thus, there is a large typology variety of dwellings: pavilion, pavilion as private collective house, private collective house, public housing, etc (see 8.2.2 Table/diagram n°8). The quality of this built environment is degraded after so many floods and a number of them are abandoned and/or seem to be.

6.7.3 Mobility

Triage neighborhood is very isolated. Only one road allows going through this area. Therefore, when the road is flooded – which is at every flood – not only does it block the inhabitant but also the evacuation team and the outsiders to travel on the territory.

6.7.2 Fig.1 Flood evacuation main access

Many inhabitants use the public transport (43%) or car (48%) to travel outside the community. (see chapter 8.2.2Table/Diagram n° 9 & 10).Thus, the connection to other communities is vital for the population inTriage.The neighborhood is also home to two children school. Both in flood area and one just in front of La Seine, first to be flooded (see chapter 6.2 - N° 10 - Fig 11 – Elementary school divided in two parts). The principal mobility is public transport or car event (see chapter 8.2.3 – Table/diagram n°9), both at huge risk because just in front of La Seine and directly impacted by common flood event (see chapter 6.5 - Fig.7 – Flood Hazard map). They are also the main evacuation access during flood.

When the water is 1 meter high the military is mobilized and after 1 meter the fireman are using boats to rescue the community. Additionally, the train station and bus station are always closed during a flood and for a community that is using at 43% (see chapter 8.2.3

Table/diagram n°9) public transport, the day to day life is irremediably affected. To escape the area during floods some even create their own foam / wood boat.

It’s good to change thedwelling built environment to create amore resilient community but the main change Triage community seems to need now is better evacuation access. The inhabitants area low incomes people, they don’t live by choice with flood, they just can’t afford to change their built environment by themselves. The minimum requirement for flood area, if the built environment isn’t resilient – or even resistant- is the evacuation mobility built environment success, which, here, isn’t.

The isolation also rise the vulnerability of the community because fewer outsiders are sharing the flood area with the local inhabitant. Due to this lack of bonding, the community receives less help and their troubles aren’t always fully recognized. Even in their common travel answers, the inhabitant of Triage neighborhood shows mobility used to go outside the area. Only half of the interrogated are traveling mostly in their community : to the kid school, the convenience store, or other small businesses like the kebab (see chapter 8.2.3 – Table/diagram n°10). Outsiders rarely stop at those shops except for the supermarket and the school.

Life is generally slowing down in the neighborhood, therefore, when a flood occurs, the community is lifeless. At least 350 to 900 people are evacuated at every flood, La Seine “fossilized Triage like a dead fish” 76

« Ca fossiliseTriage comme un de ces poissons mort dans les musées. » Quote from one the interogated. 4thApril

6.7.4 Flood & Protection

Triage community is very worried about floods. They are dangerous events damaging their built environment (see chapter 8.2.4 – Table/diagram n°11).As a result, they don’t consider flood protection and risk management effective (see chapter 8.2.4 –Table/diagram n°12). The interrogates only recognized floodwalls (54%), reservoir lakes (21%), and dikes (13%). Those three flood risk management systems were presented in chapter 3.7 as part of the old flood resistant strategy still in use nowadays. The inhabitants don’t really know what kind of flood protection or even flood resilience exists in their community or even the region. Indeed, while Le Port neighborhood has flood walls around its community, Triage doesn’t. Therefore, it can be wondered why Triage inhabitants are describing flood walls. The easy answer would be that it’s a very common flood protection and that they probably used it themselves or seen neighbors use it (see chapter 8.2.4 – Table/diagram n°13). 13% of them can’t name any flood protection. In general, Triage population doesn’t feel protected or well adjust to floods. Moreover, they all lived through at least one flood in the neighborhood (see chapter 8.2.4

Table/diagram n°15).

The point of view on resilient protection is rare. 78% of the respondents don’t know what resilience stands for and what flood resilience is or could be. The few answers are floodable green area (13%), reservoir lake (4%), and green area in general (5%) (see chapter 8.2.4 – Table/diagram n°14). It can be noticed that “reservoir lake” isn’t always considered a resilient strategy option (see chapter zzz) but the inhabitants, living far away from any of those reservoirs, still class them in “resilient strategy”.

Morethanhalfoftheinterrogatedhadtheirpersonal built environment flooded (garden, garage, dwelling, etc.) , and half of them their personal living space (kitchen, bedroom, living room, bathroom, etc) (see chapter 8.2.4 – Table/diagram n°16). Most of the floodedvictimshadtochangetheirbuiltenvironmentaftertheevent(40%- seechapter 8.2.4 – Table/diagram n°17). However, those changes were aesthetic, ( walls painting, pavement replacement in the garage, etc.) except for the repair of the ground floor walls (walls not replaced only slightly repaired) and the garden barriers (see Fig 6.7.4 n°1,2 & 3) chapter 8.2.4 – Table/diagram n°18).

Surprisingly, 21% of the not flooded respondents, after the event, decided to change something in their built environment. Their fear is on the short time return period and not so much the level of water being higher than usual. Actually the level of water is correct to the existing flood hazard map but the floods occurring more often worried

the population. Those respondents changed mostly their garden and the access to La Seine (see chapter 8.2.4 – Table/diagram n°19). Consequently, a none resilient flood community cut its physical and cultural link to the flood element, here being the river La Seine (see Fig 6.7.4 n°1,2 & 3).

6.7.4 Fig. 1 – Blocked garden / river access with concrete - 2022

6.7.4 Fig. 2 – Blocked garden / river access removed handle - 2022

6.7.4 Fig. 3 – Blocked garden / river access with concrete (wall of concrete behind barriers) -2022

Some inhabitants, almost half of the respondents (48%) , think safety is one of the biggest concerns of the community during flood (see chapter 8.2.4 – Table/diagram n°20).The safety problem is related to the fear of burglars, health issue and the mobility access (see chapter 8.2.4 Table/diagram n°22). Indeed, after the evacuation, the neighborhood is emptied of 350 to 1000 of its inhabitants. Consequently, burglars are coming at night by boat to break into dwellings and steal precious items. One of the heavily flooded interrogated inhabitants even stay in their dwellings despite the rising water to keep under surveillance burglars at night (22% of the respondents - see chapter 8.2.4 Table/diagram n°23).

The other flood victims are evacuated outside the neighborhood in a gymnasium for 7 to 21 days. La Seine flood retirement is very slow, see chapter 3.2 and 3.3. 52 % of the flood victims needed help to get food during the flood events. The government with the sub-district administration and local association (la Croix rouge & le Secour Populaire) are used to help bring food to the most endangered Triage inhabitants. Some directly in the gymnasium and others by boat to the neighborhood. About the food issue, one of the responder answered that she is used to flood and have food stock, therefore she didn’t need the government's and association's help (see chapter 8.2.4 Table/diagram n°21)

It can be concluded that Triage community resilience isn’t effective. As a result, the inhabitants with enough money are leaving one by one and areas are abandoned.

6.7.4 Fig. 4 – Abandoned garden In front of La Seine river - 2022

6.7.4 Fig. 5 – Abandoned house In front of La Seine river - 2022

7. OUTCOMES & CONCLUSION

“The human capacity for burden is like bamboo – far more flexible than you'd ever believe at first glance.”

Jodi Picoult - 2014

7.1 Introduction

This master thesis research is questioning : How the influence of built-environment can improve communities to be more flood resilient?

The resilience research focused on two communities in the south of Paris in the region Ile-de-France. Their main flood risk is link to the river La Seine. The community were chosen because of the low flood return period in their neighborhood, the high number of inhabitant and if their easily recognizable name and specific limits. With a questionnaire, a site analyse and the comparison of the two community this research is also answering :

- What type of flood resilient built environment is in those communities?

- What are the most important built environment factors to influence flood resilience?

- Which one of those factors add vulnerabilities or resiliencies and why?

As a reminder, the definition of “resilience” in this research is to “ enhance the built environment and its community fast recovery from flood ” (chapter 1.4).

7.2 Communities comparison

Tocompareboth communitiesthefollowingtablesaredividingalltheinformationfrom the past chapter into two parts : Le Port community and Triage community. There are 3 tables to help compare :

1- Community basic information table

2- Plans and maps table

3- Resilient built environment table

7.2.1 Community basic information

Le Port community in Choisy-le-Roi sub-district and Triage community in VilleneuveSaint-Georges sub-district are both in the 94 district, near Paris, in the South. Located next to each other on La Seine riverbanks, the population in Choisy-le-Roi is higher than the one in Villeneuve-Saint-Georges. However, the population in Triage neighborhood is higher than Le Port neighborhood. That's one of the reasons why many are considering Triage as a "small village all by itself". The inhabitants of Triage even gainedtheirowntrainstationandpublictransportaccessyearsago.Thetotal population of Triage is around 19 000 and Le Port 3200.

The neighborhood's size is proportional to their population, 17 600m² for Le Port and 286 400m² for Triage. However, the density by km² is 0.04 people for Le Port and 0.06 people for Triage.

The 74 600m² of the built environment in Le Port represents 22 blocks of 51 790 m² and 22 810 m² of mobility (streets, roads, etc.).

The size of Triage is more important with its 286 400m² including 258 900 m² of 12 blocks and 27 500m² of mobility built environment. Those built environment elements are more vulnerable to flood in Triage than Le Port. (30% to 80%).

The urban fabric ofTriage is much more diverse than Le Port neighborhood but Le Port has more facilities and commercial shops However the dwellings are all low/middle rise buildings when Triage has a majority of public housing and pavilions.

7.2.1 Table n°1 : Community basic information

7.2.2 Plans and Maps

Both communities are in Ile-de-France region and in the suburb of Paris in its south territory. Triage neighborhood is bigger than Le Port but both important community locations are near La Seine. During the 18th century, Le Port neighborhood was used as a harbor and Triage neighborhood was only a classic riverbank. Le Port in Choisyle-Roi was a harbor a long time before Triage neighborhood had its first community. During the 19th century, both communities changed with the industrial revolution. Nowadays, only Triage community has is still reminders of that time in its built environment. Triage was the first one inhabited.

Le Port became a residential area only during the beginning of the 2000s. During the 20th century, the industry changed the face of both neighborhoods but the biggest transformation is Triage where the population raised to 300% in 10 years. Le Port was already a harbor during the 13th century. During the 21st century, the industry glory of both neighborhoodsis long gone.Triagedidn't reallychangebut LePortredevelopment allowed inhabitants to live on the bank of La Seine.

Regardingthedensityofeachcommunity,whilethereismuchmoreinhabitantinTriage (~19300), Le Port density is higher with fewer built environment m² and population.

Both mandatoryfloodprotectionmapsarelacking information anddata.Theyonly give a short amount of flood knowledge. However, it can be said that Triage neighborhood has a larger common flood hazard area.The community is more vulnerable than Le Port.

Indeed, Le Port neighborhood has a much more recent resilient built environment than Triage. The number of the resilient built environment are also higher (12 elements compare to 7 for Triage - see 7.2.3 Table n°1 : Resilient built environment part 2). Furthermore, the built environment mobility on Le Port is more resilient for the community than Triage, which only has one main road to come and go.

7.2.2 Table n°1 : Plans & maps

7.2.2 Table n°1.2 : Plans & maps part 2

7.2.3 Resilient built environment

The following comparison table order the resilient built environment of each communities by the resiliency of vulnerability it allows. The resiliency and vulnerability are divided in four part, the flood cycle time period : mitigation, preparedness,responseandrecovery(seechapter 1.4Fig.1:Theriskmanagementcycle -Atkinsonet al,2006).LePortcommunityhas12 resilientbuiltenvironmentandTriage

7, for a total of 13 resilient built environment.

There are 9 vulnerabilities with the resilient built environment elements evaluated :

1- Waterproofing soil (concrete) ;

2- Allows population to live in flood area ;

3- Can fragilizes the building structure ;

4- Dwelling structure impacted by water and pollution ;

5- Can let dangerous elements being taken by flood (wood, soils,etc.) ;

6- Urban equipment damaged ;

7- Activity equipment disturbed ;

8- Element can be blocked by flood ;

9- Can make the known flood events less predictable ;

The less resilient built environment seems to be the possibility to allow population to live on flood area (Score of -2 for this element, see 7.2.3 Table n°1 : Resilient built environment part 1).The dwellings on the first floor, while being an interesting solution doesn’t removed the community vulnerability to flood event, same for stilts buildings.

There are 15 resilient possibilities with the resilient built environment evaluated :

1- Keeping the living space safe ;

2- Living space not impacted ;

3- Help rainfall absorption ;

4- Reduce water progress ;

5- Add water absorption ;

6- Allow activity on the flood area ;

7- Create a buffer zone between community and flood ;

8- Make the flood risk area known by other communities (risk culture) ;

9- Multiple mobility access ;

10-Add evacuation access ;

11-Day to day life preserved ;

12-Flood risk culture : help memory and preparedness ;

13-Inform and give a flood history to share ;

14-Landscape protection ;

15-Reduce water progress and give inhabitants time to prepare for flood.

The best resilient built environment for Triage seems to be the landscape resilience (score of 3 point see 7.2.3 Table n°1 : Resilient built environment part 1), an old resilient strategy, not acknowledged by the inhabitants (see 8.1.4 and 8.2.4

Table/diagram n° 14). Le port best resilient built environment is a mix of several elements : the mobility access, the flood mark as historical witnesses of flood memory, the drainage system and the creation of large green area to leave more place for rainfall absorption and allow water absorption after the flood event.

Therecovery floodperiod has more resilient elements than anyotherthree cycle period (46%) (see 7.2.3 Diagram n° 1, below)

The most resilient community is Le Port community with 11 resilient elements on its built environment (65%) with a total of12 point againstTriage communitywith a score of 6 elements (35%) (see 7.2.3 Diagram n° 2).

7.2.3 Diagram n°2

7.2.3 Diagram n°1

7.2.3 Table n°1 : Resilient built environment part 1

7.2.3 Table n°1 : Resilient built environment part 2

7.3 How the influence of built environment can improve communities to be more flood resilient ?

Le Port and Triage neighborhood resilient built environment influence can be divided into three important factors. Each of those factors influences the vulnerability and therefore the resilience of the built environment and their community.

1- Built environment basic resilience

2- Built environment mobility and evacuation

3- Built environment & risk culture

Both communities share a common language, a culture and are often flooded because of their proximity to the river La Seine. However, even if their built environment resilience to flood has some similarities, Le Port is more resilient than Triage.

7.3.1 Built environment basic resilience

The community built environment resilience positive impact is made of 3 major elements :

1- The elevation of the built environment

The elevation of the built environment includes the elevation of living space like in Triage or Le Port neighborhood, the construction on stilts (Le Port library), and a raised mobility to give better access for flood evacuation.

2- The water absorption

La Seine is rising when rainfall was or is important in the region. Therefore, the management of rainfall is important to enhance the resilience of this community and all the other ones in the territory. The main built environment resilience link to rainfall absorption is the permeable pavement like in Le Port and Triage or with Le Port drainage system. Both communities even have private gardens. While they are not for the public, those gardens were created to help the rainwater dispersal in the ground.

3- Built environment in flood area for non-vulnerable activities

The built environment can also enhance resilience through space creation for non-flood vulnerable activities. Those resilient constructions are usually sports facilities or riverbank redevelopment to allow festivals or other social activities.

4- Resilient landscape

This element is rare now in new resilient built environment development but still exists on a small scale in the past resilient elements, like in Triage and the old pavilion / public housing landscape. In general, a larger scale resilient landscape is quite rare in Ile-deFrance after 1990. The reason is simple : the region's flood strategy base a large part of its flood protection on the hydrological calculation and the reservoir lakes (see chapter 3.7). Landscape adaptation always changes the territory and therefore, the calculation and mathematical prediction of flood from the engineers are changed in the process. Consequently, the region's resilient management considers the project with that type of resilienceas adangerand avulnerability.Thelarge scalelandscapeadaptationis almost always refused by the administration itself. No matter how many times the architects are trying to prove the use of this strategy. This restriction from the authorities is very interesting and could be discussed here but the goal of this research isn’t to talk about landscape resilience.

7.3.2 Built environment mobility and evacuation

Mobility is an important element of the built environment resilience because flood disruptions can block access to the community and add vulnerability. The spatial distribution of the neighborhood change when the mobility is flooded.

Both Triage and Le Port interrogated inhabitants are expressing their worries about the mobility vulnerability. While those questions about the access to flood living areas always existed, it’s even more important nowadays with the major part car and public transport mobility plays in community development. Before the middle of the 20th century, all the community population in the region were living close to their day-today job.Accordingly, the working place was easier to access from the living space than nowadays. Our modern mobility is full of promises but when its operation is stopped, it’s the all economy and the region that stop.

Consequently, the built environment's resilience is also connected to its mobility. First, as a way to carry the community life without disruption, and secondly if the need for evacuation occurs.

Triage fails at both, with its isolated neighborhood and unique access. It can be concluded that the mobility built environment can influence the community's flood resilience when it helped opened up the flood area and keep safe access for evacuation.

7.3.3 Built environment & risk culture

1- Density, access, and resilience

The neighborhood built environment accessibility also impacts the community's relationship with its surroundings and with other communities. Le Port is very accessible, therefore, other communities are sharing the flood area and are concerned about flood resilience. Furthermore, the inhabitants of Le Port are living in shared buildings. Could be private or public buildings but the community lives in close space which means aren’t isolated and can afford repairs and a quicker “return to normal” state together? Le Port community is living in a more dense built environment than Triage and because of that, they are sharing the costs of every flood event. The price of renovation is divided by all the inhabitants and thus, they don’t worry about money like in Triage neighborhood. The densification of Le Port gives advantages and reduces vulnerability. A community is resilient when the built environment connects them, to other communities and possible help. Triage, however, is quite isolated and not well supported. While a low density could mean more resiliency, those two examples demonstrate a strong flood resilience by the spread of flood risk culture through the openness of the built environment and the sharing of flood space.

2- Flood memory marks

The second point about the built environment and flood risk culture is the memory. Le Port community doesn’t have a flood mark as a witness of flood memory but its subdistrict installed and is installing some in many areas around Le Port. That type of element helps the community to remember its flood past, can add preparedness to flood events, and avoid a false feeling of security. Flood events shouldn’t be hidden, it’s a part of the community like the community is a part of a flood.

3- Resilience acknowledgment

The last element of the resilient built environment is the community's acknowledgment of it. Indeed, many interrogated didn’t recognize the built environment's impact on their resilience. They know the area as an element exists, and they might even enjoy it, but their perception isn’t connected to resilience. This phenomenon could be explained by the lack of recognition the resilient built environment receive, which is very few. It could be only an anecdotal incident, unfortunately, it plays a big role on the

community's response to flood.As an example, in Triage neighborhood, the community doesn’t appreciate their few resilient environments and after several floods (2016,2018 & 2021), the inhabitants are repairing it with elements adding vulnerability : garden concrete barriers, replace permeable pavement with concrete pavement, barricade door access to paths near La Seine, etc.

7.4 Conclusion

This master thesis analysis demonstrates that resilience is closely related to communities’ health and wellbeing. More affluent communities are generally more resilient than those experiencing high levels of deprivation. That is the case for Le Port community and Triage. Triage is less resilient and the research shows a difficulty for its community to connect with the territory, to have a decent life and a safe environment. All of this is because their vulnerability to flood prevents a community's resilience. However, when compared to Le Port, some part of Triage built environment seems to improve the community resilience. It is not because the resilient built environment seems to not be resilient that it actually doesn’t work. The main problem with Triage is its isolation and the non-recognition of its existing resilience.

Consequently, understanding what makes a community more or less resilient through its built environment is increasingly important, not least because of the combined effects of climate change and many efforts to slow it and cope with its impacts.

Understanding community resilience can help inform a tailored response to the changes impacting it. It can also help maintain the character and diversity that are so important to national and local identity and a sense of place like for Triage & Le Port neighborhood

8.APPENDIX

8.1 Le Port neighborhood Questionnaire

Questions about gender/age and occupation

Questions about living condition in flood area

Questions about mobility in flood area

Questions about flood and protection

8.1 Table n°1: Questionnaire part 1

8.1 Table n°1: Questionnaire part 3

8.1 Table n°1: Questionnaire part 2

8.1 Table n°1: Questionnaire part 4

8.1.1 Respondents Gender / age and occupation

Respondents age

Respondents gender

Respondents occupation

8.1.1 Table diagram n° 2

8.1.1 Table/diagram n° 3

8.1.1 Table/diagram n° 4

8.1.2 Inhabitant's living location and condition in flood area

8.1.3 Mobility in flood area

8.1.3 Table/diagram n° 9

8.1.3 Table/diagram n° 10

8.1.4 Flood & Protection

8.1.4 Table/diagram n° 16

8.1.4 Table/diagram n° 14

8.1.4

Table/diagram

n° 17

8.1.4

Table/diagram

n° 18

8.1.4

Table/diagram

n° 19

8.1.4 Table/diagram n° 20

8.1.4 Table/diagram n° 21

8.2 Triage neighborhood Questionnaire

Questions about gender/age and occupation

Questions about living condition in flood area

Questions about mobility in flood area

Questions about flood and protection

8.2 Table n°1: Questionnaire part 1

8.2 Table n°1: Questionnaire part 2

8.2 Table n°1: Questionnaire part 3

8.2.1 Respondents gender / age and occupation

8.2.1 Table n° 2 Respondents age

8.2.1 Table n° 3 Respondents gender

8.2.1 Table n° 4 Respondents occupation

8.2.2 Inhabitant's living location and condition in flood area

8.2.2 Table n°5

8.2.2 Table n°6

8.2.2 Table/diagram n°8

8.2.2 Table n°7

8.2.3 Mobility in flood area

8.2.3 Table/diagram n°9

8.2.3 Table/diagram n°10

& Protection

8.2.4 Table/diagram n°11

8.2.4 Table/diagram n°12

8.2.4 Table/diagram n°13

8.2.4 Table/diagram n°14

8.2.4 Table/diagram n°15

8.2 Table/diagram n°16

8.2.4 Table/diagram n°17

8.2.4 Table/diagram n°18

8.2.4 Table/diagram n°19

8.2.4 Table/diagram n°20

8.2.4 Table/diagram n°22

8.2.4 Table/diagram n°21

8.2.4 Table/diagram n°23

REFERENCES

9.1 Figures

9.2 Tables

9.3 Bibliography

9. REFERENCES

9.1 Figures

Chapter 1.1.1

Fig.1 : Percentage of occurrences of natural disasters by disaster type (1995-2015) - In the report of “The Human Cost of Weather Related Disasters” by the Centre for Research on the Epidemiology of Disasters – 2017

OCDE data : https://ourworldindata.org/natural-disasters

Fig.2:Changein proportionofpopulation exposedtofloods–BBC,Datafrom:Global flood data base 2018 - 2021

https://www.bbc.com/news/science-environment-58087479

Chapter 1.1.2

Fig.1 : Numbers of people affected by weather related disasters from 1995 to 2015. (death are excluded from the total) - In the report of “The Human Cost of Weather Related Disasters” by the Centre for Research on the Epidemiology of Disasters – 2017

OCDE

https://ourworldindata.org/natural-disasters

Fig.2 : Number of weather-related disasters reported per country (1995-2015) –reference same as above - 2017

https://www.catnat.net/donneesstats/dernieres-actualites/20438-onu-les-catastrophesd-origines-atmospheriques-ont-fait-plus-de-600-000-morts-en-20-ans

Fig.3 : Number of floods from 1950 to 2009 by geographical region - Takeshi Fukao, 2012

https://www.researchgate.net/figure/Numbers-of-floods-have-increased-in-each-ofthe-past-six-decades-across-the-globe-Graphs_fig1_221780652

Fig 4 & 5 : Bridge of Villegailhenc – France – River flood – Google map & Franceinfo, 2018

https://france3-regions.francetvinfo.fr/occitanie/aude/carcassonne/video-aude-villagevillegailhenc-coupe-deux-endeuille-crue-1558300.html

Chapter 1.1.3

Fig.1 : Morlaix – France – River flood - Le Trégor, 2018

https://actu.fr/faits-divers/video-inondations-morlaix-sous-eaux-une-riviereville_17106064.html

Fig.2 : Village evacuation during river flood in France – Firefighters photo, 2021

https://www.pompiers.fr/actualites/intemperies-pas-de-repit-pour-les-sapeurspompiers-de-france

Chapter 1.1.4

Fig.1 : Resilience VS Resistance – Introduction to Flood Resilience -2003

https://www.yumpu.com/en/document/view/39632631/introduction-to-floodresilience-flood-management

Fig.2 : Compare between resilience and resistance city - Sustainable and Resilient Landscape Design to Flood ( Case Studies: Resilient Projects in China) Samira Ahmadkhosravi - 2018

Fig.3 : The relationship between reaction amplitude and disturbance severity for a resilient and a resistant system and a system that has both system propertiesRESILIENCE STRATEGIES FOR FLOOD RISK MANAGEMENT UNDER UNCERTAINTIES- Karin M. DE BRUIJN - 2004

Chapter 1.4

Fig.1 : The risk management cycle -Atkinson et al, 2006

http://www.floodsite.net/html/cd_task17-19/flood_management_practice.html

Chapter 2.2

Fig.1 : River flood – Paris, France – 2016

https://www.google.com/search?q=inondation+paris+2016&client=firefox-bd&sxsrf=ALiCzsZkNpvyaMMWp1T8vlrl77YCtl6bZw:1652192639007&source=lnm s&tbm=isch&sa=X&ved=2ahUKEwiUvuSakdX3AhUF3hoKHe3JD88Q_AUoAnoE CAIQBA&biw=1366&bih=615&dpr=1#imgrc=pnzRamP8f91qNM

Fig.2 : Coastal flood – Fréjus, France – 2011

https://catastrophes-naturelles.ccr.fr/-/001871_inondations-du-sud-de-la-france-ennovembre-2011

Fig.3 : Dam failure flood – Hérault, France – 2008

http://risquesenvironnementaux-collectivites.oree.org/le-guide/risques-monterritoire/risques-technologiques-majeurs/rupture-de-barrage.html

Fig.4 : Sewer flood – Malestroit, France – 2019

https://www.ouest-france.fr/bretagne/ploermel-56800/inondations-malestroit-risquede-passer-noel-les-pieds-dans-l-eau-6664206

Fig.5 : Groundwater flood– Diebolsheim, France – 2021

https://www.dna.fr/environnement/2021/07/17/diebolsheim-les-habitants-de-lancienne-cite-edf-evacues

Fig.6 : Surface water flood – South of France- Fotolia – 2022

https://www.taiwannews.com.tw/en/news/4122036

Chapter 2.5.2

Fig.1 : Bucharest Romanian capital slums before flood – 1970

https://www.bbc.com/news/magazine-24368485

Fig.2 : Bucharest Romanian capital during flood - 1970

https://www.bbc.com/news/magazine-24368485

Chapter 2.5.4

Fig.1 & 2 :Artisanal brick creation &Abrick house re-built after flood – India – 2021

https://india.mongabay.com/2019/07/flood-resistant-housing-attracts-attention-inkerala/

https://www.nytimes.com/2007/06/03/world/asia/03brick.html

Fig.3 : Graphical depiction of resistance versus resilience in response to functional service provided (y-axis) and time (x-axis) - Stovall - 2012

https://www.researchgate.net/figure/Graphical-depiction-of-resistance-versusresilience-in-response-to-functional-service_fig1_261797595

Chapter 2.5.4

Fig.1 :Analysis of resilient plan policy

Thesis, Siyu Yu, PhD - 2021

Chapter 2.5.5

Fig.1 : French resilient charter - 2016

Fig.2 : Sponge city China program example

https://www.sciencedirect.com/science/article/abs/pii/S0264837717306130

Fig.3 : Town of Dernau, Germany, Gerhard Launer,April, 2007

https://www.dw.com/en/flooding-in-germany-before-and-after-images-from-the-ahrand-eifel-regions/a-58299008

Fig.4 : Town of Dernau, Germany,Ahr River flood, Police picture, July 2021

https://www.dw.com/en/flooding-in-germany-before-and-after-images-from-the-ahrand-eifel-regions/a-58299008

Chapter 3.1

Fig.1 : Ile-de-France main rivers & waterways

Personal drawing - Data on the figure

Fig.2 : Ile-de-France Region districts

Personal drawing - Data on the figure

Fig.3 : Ile-de-France – Administrative township limits / sub-district (Communes)

Personal drawing - Data on the figure

Fig.4 : Ile-de- France – Municipality Density Population per Km²

Personal drawing - Data on the figure

Fig.5 Ile-de-France – Land use

Personal drawing - Data on the figure

Chapter 3.2

Fig.1 : Ile-de-France – Land use and built-environment (only economical / heritage and mobility) vulnerabilities

Personal drawing - Data on the figure

Fig.2 : Ile-de-France – TRI areas and flood hazard

Personal drawing - Data on the figure

Fig.3 : Ile-de-France – Topography with flood hazard & La Seine flow

Personal drawing - Data on the figure

Chapter 3.3

Fig.1 : Ile-de-France – Paris – Centennial flood – 2016

https://www.elle.fr/Societe/L-actu-en-images/En-images-A-Paris-la-Seine-en-pleinecrue-inonde-les-quais

Fig.2 : Ile-de-France – Villeneuve-Saint-Georges – fifty-year flood

2018

https://94.citoyens.com/2018/inondations-evacuations-a-villeneuve-saint-georges,2301-2018.html

Fig.3 : Ile-de-France – Draveil – ten-year flood - 2021

https://www.leparisien.fr/essonne-91/juvisy-sur-orge-91260/juvisy-draveil-l-ordre-devacuation-a-ete-donne-5854431.php

Chapter 3.4

Fig.1 : Ile-de-France – Villeneuve-Saint-Georges – Centennial flood - 1910

https://www.fortunapost.com/villeneuve-saint-georges/26472-inondations-et-crue-de1910-villeneuve-saint-georges-94-la-rue-de-paris.html

Fig.2 : Ile-de-France – Paris – Centennial flood – 1910

https://www.histoires-de-paris.fr/balade-bastille-gare-lyon-crue-1910/

Chapter 3.5

Fig.1 : Paris – Rare flood hazard data used in the region PPRI

Personal drawing - Data on the figure

Fig.2 : Map of the 1910 flood in Paris

https://fr.m.wikipedia.org/wiki/Fichier:Les_inondations_%C3%A0_Paris_1910.jpg

Chapter 3.7

Fig.1 & 2 –Anti-flood walls – Choisy-le-Roi – 2016 Flood

https://www.leparisien.fr/val-de-marne-94/vitry-sur-seine-94400/apres-la-crue-unebreche-du-quartier-des-gondoles-a-choisy-colmatee-pour-de-bon-16-02-20176686370.php

https://france3-regions.francetvinfo.fr/paris-ile-de-france/seine-saint-denis/gournaymarne-93-meme-mur-anti-crues-ne-suffit-plus-1414847.html

Fig.3 : Pannecière lake and its dam – 2008

https://openagenda.com/jep-2016-bourgogne-franche-comte/events/lac-reservoir-depanneciere

Fig.4 : Pumping station – Ile-de-Francce - Bougival-à-Louveciennes - 2019

https://www.eauxseineouest.fr/stations-de-pompages/

Fig.5 : Temporary protection named “batardeau” in French

https://sedipec.com/boutique/batardeaux/batardeau-modul/

Fig.6 : Permeable pavement

https://fr.dreamstime.com/photo-stock-trottoir-perm%C3%A9able-l-herbestationnement-%C3%A9cologique-image95569835

Fig.7 : Raised sidewalk level – Romorantin - 2018

https://www.construction21.org/france/articles/h/amenagement-du-site-matraaromorantin-illustration-de-la-resilience-dun-quartier-face-aux-inondations.html

Chapter 4.3

Fig.1 : Social-economic vulnerability- Ile-de-France – Kenji Fujiki - 2017

Kenji Fujiki PHD - Thesis - 2017

Chapter 4.4

Fig.1 : Val-de-Marne - 9 Sub-districts near La Seine

Personal drawing - Data on the figure

Fig.2 : Val-de-Marne -9 Sub-districts near La Seine – Flood hazard map

Personal drawing - Data on the figure

Fig.3 : 2 Neighborhoods– Flood hazard map

personal drawing - Data on the figure

Chapter 4.5

Fig.1 : Le Port Neighborhood – Choisy-le-Roi – Google earth - 2022

Google earth & personal modification

Fig.2 : Triage Neighborhood – Villeneuve-Saint-Georges – Google earth - 2022

Google earth & personal modification

Chapter 5.1

Fig.1 : Le Port Neighborhood – google earth - 2022

Google earth & personal modification

Chapter 5.2

Fig.1 : Le Port Neighborhood important location 2022

personal drawing & french cadatre dwg files

Fig.2 : Empty wilderness areas

Google earth & personal modification

Fig.3 : River Bank

Google earth & personal modification

Fig.4 : Library

Google earth & personal modification

Fig.5 : Parking

Google earth & personal modification

Fig.6 : Park

Google earth & personal modification

Fig.7 : Dwellings

Google earth & personnel modification

Chapter 5.3

Fig. 1 : 1756

Carte de Cassini & personal modification

Fig. 2 : 1866

Carte de l'Etat major & personal modification

Fig. 3 : 1950

Carte 1950 & personal modification

Fig. 4 : 2022

Personal drawing & french cadatre dwg files

Chapter 5.4

Fig. 1 : F.A.R. map

Personal drawing

Chapter 5.5

Fig.1 : 1910 flood on the train rail behind Le Port neighborhood

https://picclick.fr/CHOISY-LE-ROI-inondation-de-janvier-1910le-dernier273014852179.html

Fig.2 : Flood protection map : PPRI

Official Choisy-le-Roi PPRI

Fig.3 : River bank flooded 2018

Community inhabitant photo

Fig.4 : Beginning of the 2018 flood in the parking

Community inhabitant photo

Fig.5 : Street & library flooded 2016

Community inhabitant photo

Fig.6 : Park flooded 2018

Community inhabitant photo

Fig.7 : Flood Hazard map

Personal drawing - Data on the figure

Chapter 5.6

Fig.1 : Le Port neighborhood resilient built environment

Google earth & personal modification

Fig.2 : Dwellings on the first floor personal photo - 2022

Fig.3 : Creation of a large park to leave more place for rainfall absorption

Community inhabitant photo – 2019

Fig 4 : 50% permeable pavement personal photo - 2022

Fig.5 : Construction on stilts

personal photo - 2022

Fig.6 : New rainwater drainage system

Community inhabitant photo

Fig.7 : Redevelopment of the old port on the riverbank

Google earth & personal modification

Fig.8 : Gardens

Google earth & personal modification

Fig.9 : Creation of two bridges to connect the neighborhood to the rest of the city

Google earth & personal modification

Fig.10 : Raised road access

Google earth & personal modification

Fig.11 : Flood mark as historical witnesses of flood memory

https://www.reperesdecrues.developpement-durable.gouv.fr/site/piste-cyclable-bordde-seine-au-niveau-de-lavenue-de-choisy

Fig.12 : In front of Le Port : Redevelopment of the banks

https://www.slgpaysage.eu/projet_patrimoine-culturel-et-naturel_quai-des-gondolesa-choisy

Chapter 5.7

Fig.1 : Questionnaire area map

Personal drawing - Data on the figure

Chapter 5.7.2

Fig.1 :Architecture schema ideas – mainly view on La Seine - 2016

Chapter 5.8

Fig.1 : Flood evacuation main access

Personnal drawing - Data on the figure

Chapter 6.1

Fig.1 : Triage Neighborhood – google earth - 2022

Google earth & personnal modification

Chapter 6.2

Fig.1 : Triage Neighborhood important location 2022

Personnal drawing & french cadastre dwg files

Fig.2 : Old destroyed industry area

Google earth & personnal modification

Fig.3 : River path

Personnal photo

Fig.4 : Pétanque sport field

Google earth & personnal modification

Fig.5 : Supermarket

Google earth & personnal modification

Fig.6 : Only local street with many small business (pharmacy, restaurants, convenient store, etc)

Personnal photo

Fig.7 : Private harbor

Google earth & personnal modification

Fig.8 : Guinguette, typical river restaurant

Personnal photo

Fig.9 : Train station

https://fr.wikipedia.org/wiki/Gare_de_VilleneuveTriage#/media/Fichier:Gare_de_Villeneuve-Triage_IMG_6259.JPG

Fig.10 : Pétanque sport field

Google earth & personnal modification

Fig.11 : Elementary school divided in two parts

Google earth & personnal modification

Chapter 6.3

Fig.1 : Triage Neighborhood - 2016 photo

https://www.wikiwand.com/fr/Gare_de_triage_de_Villeneuve-Saint-Georges

Fig.2 : 1756

Carte de Cassini & personnal modification

Fig.3 : 1866

Carte de l'Etat major & personnal modification

Fig.4 : 1950

Carte 1950 & personnal modification

Fig.5 : 2022

Personnal drawing & french cadatre dwg files

Chapter 6.4

Fig. 1 : F.A.R. map

Personnal drawing

Chapter 6.5

Fig.1 : Triage flood 1910

https://fr.m.wikipedia.org/wiki/Fichier:Gare-de-Villeneux-St-Georges_-_cartepostale0004.jpg

Fig.2 : Flood protection map : PPRI

Official Choisy-le-Roi PPRI map

Fig.3 : Guinguette flooded 2016 Community inhabitant photo

Fig.4 : Pétanque strip flooded 2016 Community inhabitant photo

Fig.5 : Main street flooded 2016

Community inhabitant photo

Fig.6 : Train station 2018

https://www.francetvinfo.fr/meteo/inondations/val-de-marne-a-villeneuve-saintgeorges-face-aux-crues-nous-devrions-avoir-des-camions-militaires-pour-nousaider_2577058.html

Fig.7 : Flood Hazard map

Personnal drawing - Data on the figure

Chapter 6.6

Fig.1 : Triage neighborhood resilient built environment

Google earth & personal modification

Chapter 6.6.1

Fig. 1 : Permeable path

Personal photo - 2022

Fig. 1.2 : Permeable path rebuilt after flood with concrete (not resilient material)

Personnal photo - 2022

Fig. 2 : Sport facilities

Google earth & personal modification

Fig. 3 : Private gardens

Google earth & personal modification

Chapter 6.6.2

Fig.1 : Triage neighborhood resilient built environment section

Personal drawing

Fig.2 : Streets and drainage system not resilient

Personal photo

Fig.3 : Dwellings living space built on the first flood. Ground flood : only garden & garage

Personal photo

Fig.4 : Raised landscape

Personal photo

Fig.5 : Permeable path near La Seine « chemin de halage », ancient hauling path.

Personal photo

Chapter 6.7

Fig.1 : Questionnaire area map

Personal drawing

Chapter 6.7.2

Fig.1 : Flood evacuation main access

Personal drawing

Chapter 6.7.4

Fig. 1 : Blocked garden / river access with concrete – 2022 - Personal photo

Fig. 2: Blocked garden / river access removed handle – 2022 - Personal photo

Fig. 3 : Blocked garden / river access with concrete (wall of concrete behind barriers)2022 - Personal photo

Fig. 4 :Abandoned garden – In front of La Seine river – 2022 - Personal photo

Fig.5 :Abandoned house In front of La Seine river – 2022 - Personal photo

9.2 Tables / Diagrams

The following list isn’t taking into account the questionnaire tables / diagrams (see Chapter 8).

Chapter 7.2.1

Table n°1 : Community basic information

Chapter 7.2.2

Table n°1 : Plans & maps

Table n°1.2 : Plans & maps part 2

Chapter 7.2.3

Diagram n°1

Diagram n°2

Table n°1 : Resilient built environment

Table n°1 : Resilient built environment part 2

9.3 Bibliography

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2- Adaptation to climate change : soft vs. hard adaptation, Report, Stéphane Hallegatte andPatrice Dumas -CIRED andÉcole Nationalede laMétéorologie, Météo-France, 2010.

3- Communiqué de presse - Les développements socio-économiques et les effets du changement climatique devraient tirer la hausse de la sinistralité liée aux événements météorologiques graves, d’après SIGMA – SWISS RE - 2020

4- Cognition and Protection of Urban Heritage of Beijing-Hangzhou Grand Canal -

京杭大运河城市遗产的认知与保护 - 武廷海，王学荣 - 2014

5- Facts About Floods – Statistics & Data - Financial Management of Flood Risk – OECD 2022

6- Final Report on 1998 Floods in the People's Republic of China - OCHA (UN Office for the Coordination of HumanitarianAffairs) - 29 Sep 1998

7- Flood risk perception and adaptation capacity: a contribution to the sociohydrology debate, Sven Fuchs- Konstantinos Karagiorgos- Kyriaki KitikidouFotios Maris- Spyridon Paparrizos- & al.- 2011

8- Hydrology and Earth System Sciences, European Geosciences Union, page 3184, 2017

9- Procedia Engineering, Volume 192, Pages 307-312, Chapter: Vulnerability of the City Infrastructure as a Part of the Resilient City Concept, Ján Havko, Michal Titko, Jana Kováčová, 2017

10-Resilience-Oriented Urban Planning - Theoretical and Empirical Insights, Springer International Publishing, Ayyoob Sharifi, Yoshiki Yamagata, Fev. 20, 2018

11-RESILIENCE STRATEGIES FOR FLOOD RISK MANAGEMENT UNDER UNCERTAINTIES - Karin M. DE BRUIJN - Delft University of Technology, Department of Water Management, Civil Engineering – Netherlands - 2004

12-Three common types of flood explained. Flood and water damage - Z.Zurich-

July 22, 2020

13-UNDRR Report, Global Assessment Report on Disaster Risk Reduction, Geneva, Switzerland, United Nations Office for Disaster Risk Reduction (UNDRR), 2019

14-WMO Atlas of Mortality and Economic Losses from Weather, Climate and Water Extremes (1970–2019) (WMO-No. 1267), 2021

15-WHO (World Health Orgnanization)Articles on flood – 2022 Viewed on 25.04.2022 : https://www.who.int/health-topics/floods#tab=tab_1

16-Design of A Sustainable Building: A Conceptual Framework for Implementing Sustainability in the Building Sector, Peter O.Akadiri, EzekielA. Chinyio, Paul O. Olomolaiye, Buildings 2012, 126-152, 4.May 2012

17-L’intégrationmatérielledurisqueparlebiaisdesmesuresstructurelles,Chapitre 2, Environnement et société, Edition Presses universitaires du Septentrion, Helga-Jane Scarwell, Richard Laganier, p. 117-162 , 2004

18-Foundation of Ecological resilience – seminal paper - edited by Lance H. Gunderson, Craig R.Allen & C.S. Holling - 1973

19-Conception par l'opportunité pour des villes éco-résilientes aux inondations, Emilie Gascon's Thesis, p14, 2017

20-A review of the flood risk management governance and resilience literature , Article, Journal of Risk management - The chartered institution of water and environmental management (CIWEM) and John Wiley & Sons Ltd, page 291, 2017

21-Resilience and disaster risk reduction: an etymological journey ,Article, D. E. Alexander, Natural Hazard and earth system science - Institute for Risk and Disaster Reduction, University College London, London, UK , page 2708, Published: 5 November 2013

22-Learning from Floods: Linking flood experience and flood resilience, Article, Journal of Environmental Management,n° 271, Da Kuang & Kuei-Hsien Liao,page 8, October 2020

23-Livingwithfloods-resiliencestrategiesforfloodriskmanagementandmultiple land use in the lower Rhine River basin ,Article, Michaël Van Buuren, Marinus Vis, F. Klijn, Alterra - IHE - RIZA - TUD - WL|Delft Hydraulics, page 2, January 2002

24-Defining urban resilience : A review, Article, Landscape and Urban Planning, Volume 147, Pages 38-49, S. Meerow, J.P.Newell & Melissa Stults , Marsh 2016

25-Resilience definitions, theory, and challenges: interdisciplinary perspectivesSteven M. Southwick, George A. Bonanno, Ann S. Masten, Catherine PanterBrick, and Rachel Yehuda –Article in Eur J Psychotraumatol - 2014

26-What Resilience Is Not: Uses and Abuses : Ce que la résilience n’est pas, ce qu’on veut lui faire dire, Géraldine Djament-Tran, Antoine LeBlanc,Serge Lhomme, Samuel Rufat,Magali Reghezza-Zitt, p23/ 24 - 2011

27-Foundation of Ecological resilience – seminal paper - edited by Lance H. Gunderson, Craig R.Allen & C.S. Holling - 1973

28-Defining urban resilience : A review, Article, Landscape and Urban Planning, Volume 147, Pages 38-49, S. Meerow, J.P.Newell & Melissa Stults - 2016

29-The role of ecohydrology in creating more resilient cities, Iwona Katarzyna Wagner & P.Breil,, Ecohydrology & hydrobiology, Volume 13, Elsevier, p114, December 2013

30-Learning from Floods: Linking flood experience and flood resilience, Article, Journal of Environmental Management,n° 271, Da Kuang & Kuei-Hsien Liao,page 8, October 2020

31-Prospective study of the social impacts of a major flood in the Ile-de-France region. Socio-spatial disparities in the care of Ile-de-France populations in crisis and post-crisis situations: a mapped and quantified analysis of household needs, from evacuation to reconstruction – CHAPTER 4 - The post-disaster reconstruction strategy - Kenji Fujiki, Thesis , Geography. Université de Lyon (Université Jean Moulin Lyon 3), 2017.

32-A typology of resilience : rethinking institutions for sustainble developmentJohn W. Handmer & Stephen R.Dovers -Australian National University - 1996

33-Flood-resistant housing attracts attention in Kerala -Article - Mongabay - by K. Rajendran on 24 July 2019

34-Planning for resilience and climate change in the U.S. and the Netherland - Siyu Yu, phD,AICP - Tongji - 2021

35-NOACCIDENT, Resilience and the inequality of risk - Briefing paper - Oxfam

36-International Policies, Practices and Discourses - Volume 7 - Chandler, 2014Chandler, D. (2014). Joseph, (2013); Walker & Cooper (2011); Evans & Reid, (2014)- Issue3:ThePolitics ofResilience, Editedby: Clemence Humbert and Jonathan Joseph Resilience: Article , The governance of complexity –David Chandler - Pages 304-313 - 2019

37-Community recovery and resilience building in the aftermath of flood hazards in the small island developing state of Mauritius, Anoradha Chacowry, The University of Gloucestershire, p.71, June 2014

38-Mayer, B. A Review of the Literature on Community Resilience and Disaster Recovery. Curr. Envir. Health Rpt. 6, 167–173 - 2019

39-Impacts of Missing Data in Risk Management - Thesis - PARIS 1- Patricia Dos santos - 2021

40-L’Île-de-France et les Franciliens - Xavier Panon – Decitre – France - 2004

41-10 questions sur la biodiversité en Ile-de-France - Eric Glover - T&O edition2010

42- Que faire des eaux d’inondation ? Le cas des villes de Gaule - CécileALLINNE - MCF, Université de Caen Normandie, Centre Michel de Boüard /CRAHAM –UMR-6273 - 16 octobre 2020

43-Les lendemains des catastrophes naturelles au Moyen Âge - Actes du 16ème colloquedelaVillaKérylos àBeaulieu-sur-Mer -Jacques Berlioz- Publications de l'Académie des Inscriptions et Belles-Lettres - 2006

44-Rapport, Agence de l'Eau Seine-Normandie - 1992 à 1998, l'IIBRBS, en partenariat avec l'État, la région Île-de-France - 1998