Wu5 hanoi analyse internetversion by stefanie.dens

WATER URBANISM

Hybrid Dykes in Yen So Hanoi, Vietnam

Master of Applied Sciences and Engineering: Architecture

Authors

Stefanie Dens

Laura Rijsbosch

Promotor

2010-2011

Prof. Dr. Kelly Shannon Co-promotor

Prof. Guido Geenen

© Copyright by K.U.Leuven Zonder voorafgaande schriftelijke toestemming van zowel de promotor(en) als de auteur(s) is overnemen, kopiëren, gebruiken of realiseren van deze uitgave of gedeelten ervan verboden. Voor aanvragen tot of informatie i.v.m. het overnemen en/of gebruik en/of realisatie van gedeelten uit deze publicatie, wend u tot de K.U.Leuven, Faculteit Ingenieurswetenschappen – Kasteelpark Arenberg 1, B-3001 Heverlee (België). Telefoon +32-16-32 13 50 & Fax. +32-16-32 19 88. Voorafgaande schriftelijke toestemming van de promotor(en) is eveneens vereist voor het aanwenden van de in dit afstudeerwerk beschreven (originele) methoden, producten, schakelingen en programma’s voor industrieel of commercieel nut en voor de inzending van deze publicatie ter deelname aan wetenschappelijke prijzen of wedstrijden. © Copyright by K.U.Leuven Without written permission of the promotors and the authors it is forbidden to reproduce or adapt in any form or by any means any part of this publication. Requests for obtaining the right to reproduce or utilize parts of this publication should be addressed to K.U.Leuven, Faculty of Engineering – Kasteelpark Arenberg 1, B-3001 Heverlee (België). Telefoon +32-16-32 13 50 & Fax. +32-16-32 19 88. A written permission of the promotor is also required to use the methods, products, schematics and programs described in this work for industrial or commercial use, and for submitting this publication in scientific contests.

WATER URBANISM

Hybrid Dykes in Yen So Hanoi, Vietnam

Thesis presented to obtain the degree of Master of Applied Sciences and Engineering: Architecture 2010-2011

AUTHORS Stefanie Dens, Laura Rijsbosch PROMOTOR Prof. Dr. Kelly Shannon CO-PROMOTER Prof. Guido Geenen READERS Prof. Dr. Bruno De Meulder, Tuan Pham Anh,

Dr. Loan Pham Thuy

Acklowledgements

We are heartily thankful to our promoter Prof. Dr. Kelly Shannon , her encouragement and strict guidance widened horizons. Assisted and guided with inspiration by Prof. Guido Geenen and Prof. Bruno De Meulder, we were able to walk through an intriguing design process. We would like to thank Prof. Loan Pham Thuy for receiving us in Hanoi, and Tuan Pham Anh, to introduce us to his case study Yen So. Thank you Erik and Thibaut, for the great time we had in Hanoi, and for introducing us to the world of KTTâ&#x20AC;&#x2122;s. Furthermore we greatly appreciate the interesting debates and working moments we had with the Water Urbanism team. Especially we would like to thank Pierre for sharing his opinion and for the wonderful times we had together while working. Laura: Firstly I would like to thank Stefanie for being an incredible partner. Furthermore thanks goes to Jasmin, for her advice on English writing, Hanne for the great tea times we have had this year and Julie for always being interested. Lastly I want to express my gratitude to my parents for their moral support during the whole period and for being there unconditionally, Thank you! Stefanie: Enriched by this year I would like to thank my family, Laura, Sam and Bert. Thank you Guido for sharpening my wits over the last two years. Thank you Sneha, for always being near, though far away. And thank you Pierre, for teaching me to live with the floods. 7

Preface

This thesis is a component of the Water Urbanism Thesis Studio which focuses on the concept of resilience in 4 cities with a water specific context. Through design research, Arequipa (Peru), Tainan (Taiwan), Can Tho (Vietnam) and Hanoi (Vietnam) are included in the debate. Hanoi, the 1000 year old capital of Vietnam, was found in a bend of the Red River, and has developed hand-in-hand with an extensive dyke system. Nowadays, due to swift urbanisation and the predictions of climate change, Hanoiâ&#x20AC;&#x2122;s water challenges are on the rise. The hypothesis is that a hybrid dyke that integrates engineering, urban design and management can convert these challenges into an opportunity to deal with the contemporary â&#x20AC;&#x201C;often urban- floods and droughts. Dykes can become new hybrid structures that work across scales and disciplines. To research on the hypothesis this thesis focuses on the dykes in the area of Yen So, a case study area sized 8 by 12 km and being the lowest area in the southern periphery of Hanoi. The aim of the thesis is to link the logics of water management, infrastructure, urbanisation and landscape, in order to wrap them up in a strategic design that is founded on a strong analysis of the current water and urbanisation problematic of Yen So and therefore Hanoi. The thesis starts with a cross scale analysis, zooming in and out with relation to the Yen So area and its dykes. This way each chapter deals with a different scale: the first chapter takes into account the scale of the Red River Delta, the following ones deal with scale of Hanoi, Yen So and the floodplain of Yen So, while the last chapter ends with a specific look on the dyke. Parallel to the research a design has developed which concludes the series of booklets. The proposed design projects focus on the scale of the floodplain and its dyke system and on the concepts of resilient design. 9

Table of Contents 8 12

Preface Situating Yen So

18 26 64 148 192

Red River Delta Hanoi City of Lakes Yen So Lake Collector Red River Floodplain Dyke Connector

236

Conclusions & Design Introduction

18 RED RIVER DELTA

26 HANOI

City of Lakes

28 1. Landscape of Meanders 32 2. Urban Sprawl 42 3. City Floods 48 5. City of Lakes

64 YEN SO

Lake Collector

148 RED RIVER FLOODPLAIN

66 1. Yen So Water History

150 1. Sections

80 2. Water Collector

166 2. Agriculture

86 3. Urban Tissues

174 3. Networks

A. Methodology B. Structure and Public Space C. Urban Growth D. Connectivity E. Difference in Planning F. Profession, Topography & Housing

184 4. Planning for the Future

192 DYKE

Connector

A. Methodology B. Water Barrier C. Changing Atmosphere D. Local Events E. Village Connector F. Sequence of Openings

0. Situating Yen So Vietnam

Vietnam on a world scale

The Socialist Republic of Vietnam is situated in South East Asia and bordered by China, Laos, Cambodia and the South China Sea (referred to as East Sea). Vietnam had 87 270 754 inhabitants in 2009, and covers approximately 331 688 km². The capital of Vietnam is Hanoi, situated in the North, in the middle of the Red River Delta. Vietnams topography and location make it a country of WATER and MOUNTAINS. It has a coastline of approximately 3260km in which 114 small and larger rivers flow out [WEPA 2011]. The largest of these is the Mekong which rises in Tibet and flows out in the south of Vietnam. The second largest is the Red River (or Song Hong in Vietnamese), rising in the Yunnan Province of China, and flowing out in the north. Furthermore the country is mountainous in the Northwest and in the central highlands. The fact that the relation between water and mountains have always been acknowledged by the Vietnamese, is written down in lots of legends that have passed many generations: “Hung King 18th (the last Hung Kings) had a beautiful daughter. When she of the age to marry, both Son Tinh (the mountain genie) and Thuy Tinh (the water genie) came to seek her hand. The King asked them special things as the wedding gifts and promised that his daughter could marry the first who returned with the required wedding gifts. The following day, Son Tinh came first, was married to the Princess and took her to the mountains to live with him. Thuy Tinh was very angry and decided to control his soldiers [aquatic monsters] to fight Son Tinh. He failed because when he ordered the waters to rise above the mountains, Son Tinh raised the mountains higher than water level. The two men battled it out year after year, the result being the nation’s strong geography of low-lands that are yearly inundated and high, rugged mountains.” [Pham Anh 2010] Vietnam has a tropical to subtropical monsoon CLIMATE, with a south monsoon that sets in from May to September, and a north monsoon that sets in from October till April. The south monsoon is characterised by a south to southeast wind, taking along torrential rains from typhoons that move in from the South China Sea, while the north monsoon only knows north to northeast winds [vietnamembassy.org 2007]. As the monsoon passes, rainfall rises up to 550,5mm as was the case for Hanoi in July 2009. The remainder of the year, rainfall is very light: 1,2mm was noted in November 2009 in Hanoi [sgo.gov.vn 2011]. 12

CHINA

Yunnan province

r i ve

Me k on gr i ve r

Hanoi

MYANMAR

Gulf of Tonkin LAOS

THAILAND

Andaman Sea M ek on g

100

250 km

Vietnam, country of water and mountains

South China Sea

0. Situating Yen So Red River & Mekong Delta

Red River Delta

water

dyke

55km

Mekong Delta

water

55km

The Red River Delta is situated in the northern lowlands of Vietnam, and is together with the coastal zones and the Mekong Delta the place where 58% of the population of the country lives [TranDuc et all. 2004]. The Red River itself has its ORIGIN in the Yunnan province and is about 1 149 km long, of which 510 km flow in Vietnam and 115 km flow in the province of Hanoi [Pham Anh 2010]. The water levels varies between 1,4 and 14,3 meters and the river has an average flow of 2,640 m3/second and a total flow of about 83.5 million m3/year where the velocity of water can reach to 3.45 meters per second. [NHPI 2010: 39 in Pham Anh 2010]. The name of the Red River betrays the fact that it is carrying a great deal of ALLUVIAL SEDIMENT. “On average, the water of the Red River carries 1000g of silt per 1 cubic meter and about 114-115 million tons per year [NHPI 2010: 58]. The quantity of water and silt are different throughout the year, where there is 80-85% of water [NHPI 2010: 2] and 90% of silt [NHPI 2010: 59] in the rainy season (from May to September)” [Pham Anh 2010: 1]. Furthermore the Red River Delta is characterized by its extensive DYKE SYSTEM that is the result of a dyke construction policy from generation to generation in order to be able to use the water for irrigation, drainage and communication. Only later the dykes where used to protect settlements for flooding as well. The dyke system along the Red River Delta measured 3000 km in 1945, and increased to 8000 kilometres by 1996, of which 3000 km are sea dykes and 5000 km are river dykes. Of this 5000 km the Red River dyke systems comprises 1580 km and 750 km are used for the Thai Binh River [Gliedman 1972: 6 in Pham Anh 2010]. As Gliedman states: “These became the most important means for protecting land and controlling the water in the agricultural fields. Without the dyke system, two-thirds of the Red River Delta world be inundated in the summer” [Gliedman 1972: 6 in Pham Anh 2010]. In sharp contrast to the Red River Delta in means of dyke building is the Mekong Delta, as is shown on two maps on the same scale above. Where the north has completely embanked in the Red River, the south has given the Mekong no restrictions, following a mentality of living with the water in stead of fighting against it. 14

Lo r i ve r

T ha i ve r o r

Re d

r i ve

Ba Vi Mountains

i ver

Re dr

Da r

i ve r Gulf of Tonkin

15 km

Hanoi, heart of the Red River Delta

city

dyke

water

0. Situating Yen So Yen So, southern gate to Hanoi

Hanoi, founded by Emperor Ly Thai Tho in 1010, is situated in the heart of the Red River Delta and is the second largest city of Vietnam. The 1000 year old city was found in a bend of the Red River and carries this fact in its name. Thereby Hanoi became a city known for its extensive water bodies, a city of lakes in which the relation between water and inhabitants has always been a key element. As the city started to grow fast, from 2 767 700 inhabitants in 2000 to a 3 228 500 in habitants in 2007, its borders where redrawn in 2008, giving rise to a city of 6 472 200 inhabitants, of which the numbers show a rapid rural-urban migration [sgo.gov.vn 2011]. Due to the URBAN PRESSURE, nowadays agricultural land is being claimed, and lakes are being filled in with sand in order to become flat new building plots, while culture is neglected. The location of Hanoi makes it very prone to the PREDICTIONS OF CLIMATE CHANGE, as the city is nowadays already suffering flash floods from the mountains, monsoon typhoons that come along with southern winds, high river floods during the summer from June till October, and in cases of extreme rainfall Hanoi knows city floods as well. The last named is possible since the rivers sediment has heightened up the river by flooding each year, thereby levelling the river and its bed higher than the city, which makes it impossible for the water to naturally drain out. It is in this water context of Hanoi that the YEN SO CASE STUDY AREA of 8 by 12 km is chosen, aiming at taking together the key elements of Hanoi’s current problematic of urban growth and the predictions of climate change. Situated in the southern periphery of Hanoi, Yen So forms the pivot between agriculture and city. It is the place where land is claimed for urbanisation and where agriculture is slowly being pushed away. As it is the lowest area of Hanoi, Yen So is a real lake collector, connecting several water bodies and collecting the majority of Hanoi’s lakes. With the building of the Yen So Pumping Station in 2000, Yen So became an indispensable key element in Hanoi’s water management, as the role of the station and the surrounding lakes is to purify the water from the To Lich Channel, and to pump the gathered water of the city to the river, preventing the city from city floods. Moreover it is the place where the floodplain of the Red River is at its widest between the dykes and where the river more or less can follow its natural rhythm of flooding and withdrawal, of shifting over time. 16

3 km

Yen So study area, 8 by 12 km

city

dyke

water

Red River Delta

Flow of the Red River

THAO RIVER

DA RIVER

Son La Reservoir

The Red River Delta and its main tributaries. The flow of the Red River is highly influenced by the four main reservoirs. Map made by Thibaut Visser

Tuyen Quan Reservoir

LO RIVER Hac Ba Reservoir

RED RIVER

Hoa Binh Reservoir

GULF OF TONKIN

water

Hanoi

border of Vietnam

5 10

50km

Lo River

Thao River

Red River

Van Coc reservoir

Day Dam

Tich River

Day River

HANOI Da River

Bavi Mountains

water dyke

Red River Delta

0 1

5 km

Tuyen Quang

Hoi Quang

Thac Ba

Lo R iver

Lai Chau

Son La Da

R iv

er D ay

Hoa Binh

R ive r

water Hanoi

reservoir hydropower

border of Vietnam

0 10 20

50 km

Location of the different reservoirs

The water in the RED RIVER DELTA manifests itself in various ways depending on the changing natural conditions. The Bavi Mountains, the Day River and the Red River are strong elements going north to south creating different atmospheres by means of different water typologies. In the west the water in the Bavi Mountains follows the natural curves of the land flowing down to lower areas in which the Tich River at the foot of the mountains collects these small waterways. To the east a wide irrigation network following the rectangular grid of the fields covers the plain of the delta. Two main rivers, the Red River and the Day River structuralize the plain on a large-scale. The two are bounded by dykes dividing the land in an area inside the dyke and an area outside the dyke. The water from the Red River comes from three tributaries: The Thao, Da and Lo River. These three rivers collect the rainwater and melt water coming from the mountains.

To reduce the stress on the dyke system two reservoirs were constructed upstream. In 1972 the Thac Ba reservoir on the Chay River was completed with a total storage of 3.6 billion m続 and in 1989 the Hoa Binh reservoir on the Da River was constructed with a total storage of 9.45 billion m続. The last mentioned had a high impact on the reduction of floods in the Red River. Nowadays two more reservoirs are being completed: the Tuyen Quang reservoir with a total storage of 2.3 billion m続 and the Son La reservoir with a total storage of 9.26 billion m続 [Huntjens et al. 2007: 3]. During dry season, the reservoirs are used to provide the minimum flow of water in the rivers for agricultural and industrial purpose.

The city Hanoi is founded in a bend of the Red River. Its location in the floodplain of the Red River Delta makes the city very vulnerable for flooding. Due to heavy rainfall, the water level of the Red River fluctuates between 2 and 14 metres above sea level. The average elevation of the delta is around 5 to 7 metres above sea level. Therefore a whole system of dykes along the Red River and the Day River is established to protect the settlements from flooding. But the high water level during rainy season causes a high risk if the dykes fail during floods. 23

Van Coc reservoir

Day Dam

water dyke

Connection Red River with Day River

0 0.5 1

2 km

Day Dam [Kock 2006]

Together with the dyke system and the reservoirs, a third measure is put in place to prevent flooding in Hanoi. A diversion through the Day River is used to decrease the water flow. “The Day River Flood Scheme was implemented in 1937, with the construction of the Day Dam. In the past large parts of the Day River region were annually flooded due to the absence of dykes in the area between Ha Don and Hoa Binh and in the low area downstream of Phu Ly [Kok 2006: 6]. Because of this the French Government decided to construct the Day Dam with movable gates, some 8 km downstream of Hat Mon. This location was chosen because the dykes of the Day River and the Red River used to converge there. However, because of the dam the floodplain of the Red River at Hat Mon became higher and higher, preventing the Red River water at low flows from entering the Day River and greatly reducing the releasing capacity of the structure [Kok 2006: 7, Van Sinh 2005: 480]. “This prompted the construction of the Van Coc sluices commissioned in the year 1966 to facilitate passage of large floods” [Kok 2006: 7]. At present the Day River flood diversion thus consists of three parts: The Van Coc Gate and Hat Mon spillways both to the west and east of the sluice, the Van Coc reservoir and the Day dam. In case of flood diversion, the water is initially released through the Van Coc sluice and over the Hat Mon spillways into the Van Coc reservoir. This retention area enclosed by dykes can temporarily store the floodwater before it

is released through the Day Dam into the Day River. The whole diversion system was designed to divert 5000 m³/s from the Red River [Van Sinh 2005: 480, Le Tuan et al. 2004: 344-345]. “If the Hoa Binh and Thac Ba reservoirs operate with their full flood relieving capacity, the water level at Hanoi reaches 13.40 m, and the General Department of Meteorology and Hydrology of Vietnam predicts that the flood water level continues to rise quickly, the flood must be diverted into the Day River”[Le Tuan et al. 2004: 344, quoting Institute of Meteorology and Hydrology, 2000].” [Visser 2010]. In 2008 the system of dykes, reservoirs and diversion strategy could not protect Hanoi. Also with the construction of the Hnghe Hanizu Yizu Dam in the Yunnan province in China, the Vietnamese people can not predict precisely when the water will rise and endanger the citizens of Hanoi since the Chinese authorities can decide at every moment when they will open the dam. Strong flood management is necessarily to handle with the situation. Especially today when due to climate change more and more flooding will occur, since there are increasing instances of rains heavier than 100mm/hour.

Hanoi

city of lakes

Hanoi

city of lakes

1. landscape of meanders In this section the natural conditions of the river are pointed out. Through mapping in time the particularities of the dynamical play of the river are shown.

The Red River has changed dramatically over time. Previously the river flow was completely different than it is today. In the Holocene period the river bed of the Red River changed over the years. The topography determined its direction. The river was a part of the dynamical play of nature. When settlements started to develop in the floodplain of the Red River, people tried to control the water flow by the construction of numerous dykes and hydraulic works.

One of the first dykes was built in 1077 at the level of State along the Cau River [Pham Anh, Shannon 2009b: 3 based on Le, 1997: 299]. The dyke system limited the

area where the river can meander. In time the river bed was increasingly determined by the control of the human beings. The river became less dynamic and more static. In the Yen So area, the two dykes at both sides of the Red River stand the widest from each other, leaving the most space for the movement of the river.

Cartographic research shows that in the twentieth century the dynamical play of the Red River was still more present in this area than in other places near Hanoi. The river bed moved from west to east and headed back to the west. Previously the West Lake was part of the Red River, but today the dyke lies between the river and the West Lake and separates them from each other. The dykes do not only control the water, they also have shaped the river itself.

Holocene period

1911

1935

1996

2000

2010

water dyke

0 1 2

5 km

Yen So study area

0 0.5 1

2.5 km

Flow of Red River in time

water in different time periods

Hanoi

city of lakes

2. urban sprawl 10 October 2010 was the celebration of 1000-year Hanoi. During its existence Hanoi is transformed from a single citadel to a city at world scale. Water, population growth and political regimes are important elements of this transformation. In this section an overview is given of Hanoiâ&#x20AC;&#x2122;s urban growth in relation to the evolution of lakes and the growth of the dyke system. This way there will be a quick insight in the current problems of Hanoi. In the first part the history of Hanoi and the regulations concerning its growth is examined. The second part ends with an overview of the changing dyke system in time.

In the centre of Hanoi, houses are built next to the railway, leaving just enough space to let pass the train going to Ho Chi Minh City in the south of Vietnam. 34

Urban Evolution of Hanoi First, an overview of all the evolutions: maps showing the spatial development of Hanoi are combined with the parallel evolution of dyke transformations, building of bridges, flood events and political periods.

1885

1935

urban growth water dyke 0

5 km

dyke transformations

1926

1913 1915

1898

1873

building of new bridges flood events changes of political regime

2008 2010

2005

2002

1996

1986

1983

1979

1971

1945 1972 2010

Hanoi

has

seen

some

strong

URBAN

The history of Hanoi is characterized by the rise and fall of various dynasties. Hanoiâ&#x20AC;&#x2122;s origin dates back to more than 2,000 years as capital of the Au Lac dynasty, named Co Loa. In 1010 the first King of the Ly Dynasty decided to move the capital from Hoa Lu to Thang Long, nowadays Hanoi. Today, the year 1010 is seen as the date of creation of Hanoi [Ngoc Nghiem 2010: 1]. In the Feudal period Hanoi went through several stages of occupation and transformation. In that time the city mainly consisted of three elements: the Royal Citadel, the handicraft villages along the West Lake side and the commercial district (today called 36 streets district) between the citadel and the Red River [Ngoc Nghiem 2010: 2]. The French occupation from 1783 until 1945 changed the city dramatically. The walls of the Citadel were destroyed because they were seen as a symbol of the old Vietnamese imperial regime [Logan 2000: 80]. Also part of the big structural works was the construction of a new urban tissue in the south of the city. This was based on the ongoing European planning structure which consisted of a grid pattern of streets of 20-30 metres wide with tree lined lanes and large houses for the French settlers [Logan 2000: 92].

Due to the construction of the first bridge (Long Bien bridge) in 1902 and the construction of new industrial sites in the Gia Lam district in the east of Hanoi in 1960s, the city started expanding towards the east side of the Red River [Logan 2000: 77; Kammeier et al 2002: 382].

Since the introduction of Doi Moi (means renovation, it refers to the economical reforms to develop towards a socialist-oriented market economy) in 1986 the national policy of central planned economy changed to a decentralized market economy [Kammeier et al 2002: 374]. From now on also private and foreign companies could carry out investments which resulted in a rapid increase of the urban development. The boom caused illegal occupation of land and chaos in urban development since there was no strict master plan to follow. Master plans in Vietnam were considered more as wall-decoration in the offices of Peoples Committees (socalled Quy hoach treo) than as a serious answer to the ongoing urban developments [Coulthart 2006: 27]. The urban management was not adequately adapted to the rapid new processes. The periphery underwent strong urbanization. This rapid expansion is still going on today. Illegal settlements are arising in the outside dyke area. Normally a land use certificate from the government is needed, but because the administration is overloaded and the planning management is more focussed on the investments of state resources, the government is not able to guide or control the private developments. Most illegal housing construction is undertaken without a building permit, but nonetheless it is recognized by the public and informally, by the government [Kammeier et al 2002: 376-377 383]. Nowadays, approximately 160 000 inhabitants are living in the outside dyke area [HAIDEP final report 2007: 135]. The indistinct regulations have permitted the uncoordinated growth of the city. The city is expanding and densifying in a way that takes no account of the liveability of the city. Since the Doi Moi, the government is unable to lead the changes towards a sustainable growth. Nowadays, the master plan of 2030 has to structure the uurban ba eexpansion. pa s o With W t this t s master aste as te plan, plaa , the pl t e government gove go ve e t w wants a ts to coordinate ccoo oord rdin inat atee the the urban urba ur bann ex expa expansion pans nsio ionn towards towa to ward rdss areas area ar eass in the the west wes w estt an and d north nort no rthh of Hanoi. Han H anoi oi..

Long Bien

Thang Long

In the last 40 years, the city has increased enormously. This is partly due to the changing policy of the government. During the French colonial period, private ownership of land was a normal practice. However owe weve ve after a te the t e August ugu gust st 1945 9 5 revolution, evo ut o , tthee northern o t e p part a t of o Vietnam Viet Vi etna nam m followed follllow fo owed ed tthe he SSoviet ovie ov iett Co Comm Communist mmun unis istt mo mode model. del.l. LLan Land and d be beca became came me property prop pr oper erty ty o off th thee St Stat State atee an and d it w was as tthe he SSta State tate te w who ho ccon controlled ontr trol olle led d al alll th thee

developments. The central bureaucracy mechanism worked very slowly and five plans had to be developed before implementation could start [Kammeier et al 2002: 377].

Thanh Tri Vinh Tuy

time,

Chuong Duong

TRANSFORMATIONS.

building of bridges

2010

Now 2002 2005

1983

1979

Socialism 1945

French colonial 1898

1873

Feudal period

0.5

2 km

water dyke

bridges from north to south

urban growth 1885

1935

1972

2000

2010

Thang Long | Long Bien | Chuong Duong | Vinh Tuy | Thanh Tri

Hanoi has grown with the DYKE SYSTEM since the site where Hanoi is constructed lies below the level of the Red River during wet season [Logan 2000: 32]. The first dyke along the Red River in Hanoi was built in 1108 under the Ly Dynasty [Pham Anh, 2010: 21 based on Le 1997: 299]. The first dykes were low earthen walls, strengthened with bamboo and spikes, with a small walking path on the top [Logan 2000: 32]. During the years, Vietnam has increased its dyke system. In 1729, the heightening of dykes was combined with the digging of new rivers, dams and reservoirs [Pham Anh, Shannon 2009b: 5 based on Phan 1995: 141].

In 1873 the French occupied Vietnam. Under the control of the French, a lot of lakes in the centre were filled with land which led to the loss of permeable ground surfaces in the city and furthermore to more water problems during heavy floods. The To Lich River was cut off from the hydraulic network and canalized, resulting in a disruption of the ecological and socio-cultural balance. [Pham Anh, Shannon 2009a: 6].

As a consequence of several catastrophic floods, the French introduced a new water control network. Between 1918 and 1935 they repaired and improved the dykes with new techniques and created a nnew ew profi pro p rofifile ffor or iit: t: a sste step tep p dy dyke ke p pro profi rofifile ((fifigu gure gure). re). ). IInn th thee following follllow fo owin ingg years year ye arss fr from om 1193 1937 9377 to 1944, 1194 944, 4, the the dyke dyk d ykee di didn didn’t dn’t ’t b bre break reak ak o onc once. nce. e. H How However owev ever er iinn 1945, 1945 19 45,, pa part partly rtly ly due due to to the the destruction dest de stru ruct ctio ionn of tthe he d dyk dyke ykee sy syst system stem em d dur during urin ingg th thee independence inde in depe pend nden ence ce war, war w ar,, a bi bigg floo ood d in inun inundated unda date ted d se seve several vera rall de dens densely nsel elyy po popu popupu-lated late la ted d pr prov provinces ovin ince cess of tthe he R Red ed R Riv River iver er D Del Delta elta ta [P [Pham [Pha ham m An Anhh 20 2010 10 : 2211 ba base based sed d on Nguyen 89,157, 270; 2009b 5-6]. Nguy Ng uyen en 2007: 2200 007: 7: 889, 9,15 157, 7, 2270 70;; Ph Pham am A Anh nh eett al 2200 009b 9b : 55-6 -6]. ].

Af terr heavy After Afte heav he avyy figh ghti ghting ting ng between bet b etwe ween en the the FFre French renc nchh and and the the Viet Viet Minh, Min M inh, h, Hanoi Han H anoi oi beca be became came me tthe he ccap capital apit ital al o off an iind independent ndep epen ende dent nt N Nor North orth th V Vie Vietnam ietn tnam am iinn 19 1954 1954. 54.. Th Thee Nort No North rthh Vi Viet Vietnamese etna name mese se SSta State tate te ssta started tart rted ed tto o focus focu fo cuss ag agai again ainn on tthe he eela elaboration labo bora rati tion on of tthe he d dra drainage rain inag agee an and d ir irri irrigation riga gati tion on ssys system. yste tem. m. A fful full ulll ca cana canal nall ne netw network twor orkk wa wass pu putt in p place lace la ce aand nd iinn fo four ur yyears ears ea rs ttim time, ime, e, 2250 2500 5000 pu pump pumping mpin ingg st stat stations atio ions ns w wer were eree bu buil built iltt in thee Re th Red d Ri Rive River verr De Delt Delta ltaa [F [Fontenelle [Fon onte tene nellllee 20 2001 2001: 01:: 8 quoted quot qu oted ed by by Vo Vo,, Nh Nhan an T Tri ri 1196 1967, 967, 7, quoted Ivon-Tran 1994]. quot qu oted ed b byy Iv Ivon on-T -Tra rann 19 1994 94]. ]. A Also Als lso o bi bigg re rest restorations stor orat atio ions ns o off th thee dy dyke ke w wer were eree accomplished; acco ac comp mplilish shed ed;; th thee dy dyke dykes kess we were re hhei heightened eigh ghte tene ned d by a ccon concrete oncr cret etee wa wallll aand nd could coul co uld d re resi resist sist st flood ood w wat waters ater erss up tto o 13 13.3 13.30 .300 me mete meters ters rs [[Pham Pham Ph am A Anh Anh, nh,, Sh Shan Shannon anno nonn

In 1971 the most devastating flood in 100 years occurred in Hanoi. The water level reached the level of 14.13 metres and the dyke broke at three locations, affecting the lives of 2.7 million people and causing an economic cost of around 78 million USD [World Bank 2003: 26].

After this disaster, a new concrete wall was constructed on top of the dyke [Interview with Tran Van Dien by Pham Anh, Shannon 2009b: 10].

During the Doi Moi, knowledge about flood control and dyke maintenance was updated and improved with the help of international comities. The slopes of the dykes were improved with concrete embankments against erosion and the government decided to construct local roads next to the dyke to protect the dyke from the urbanization pressure [Pham Anh, Shannon 2009b: 10]. From 1996 to 2001 a project supported by the Asian Development Bank upgraded the dyke on the right bank of the Red River. The top was widened up to 10-16 meters and the slopes were strengthened once more [NHPI 2010 quoted by Pham Anh, Shannon 2009b: 10].

The rapid urbanisation and land filling are changing the permeability of the ground which together with the changing climate increase thee risk th risk of of floo oods oods. ds.. An eexa example xamp mple le o off th this is iiss th thee floo ood d of N Nov November ovem embe berr 2008 20 08 w wit with ithh a de deat death athh to tollll o off 94 p peo people eopl plee an and d an eest estimated stim imat ated ed d dam damage amag agee co cost st of 430 430 million milillilion m on U USD SD [P [Pham [Pha ham m An Anh, h, SSha Shannon hann nnon on 2200 2009a: 009a 9a:: 8]. 8]. In conclusion, ccon oncl clus usio ion, n, Hanoi Han H anoi oi can can not not exist eexi xist st without wit w itho hout ut the the d dyk dyke ykee sy syst system; stem em;; th thee dykes dyke dy kess pl play ay aann im impo important port rtan antt ro role le o onn th thee sc scal scale alee of H Han Hanoi. anoi oi.. Ho Howe However weve verr lo look lookok-ingg to the in the several ssev ever eral al dyke dyk d ykee failures, faililur fa ures es,, the the dyke dyke ssys system yste tem m ca cann no nott be tthe he unique uniq un ique ue element eele leme ment nt o off th thee wa wate water terr ma mana management nage geme ment nt aaga against gain inst st flo ooding. ood odin ing. g. As As mentioned ment me ntio ione ned d in the the ssec section ecti tion on ccon concerning once cern rnin ingg the the delta, delt de lta, a, new new ways way w ayss of w wat water ater er management mana ma nage geme ment nt need nnee eed d to be be developed deve de velo lope ped d and and the the whole whol wh olee wa wate water terr ne netw network twor orkk at tthe he ssca scale cale le o off th thee de delt delta ltaa ha hass to b bee ta take taken kenn in into to aacc account. ccou ount nt..

2009b: 2009 20 09b: b: 9]. 9].

dyke transformations flood events

2008 2010

2002

1996

Now 1986

1971

1945

Socialism 1926

French colonial 1913 1915

1873

Feudal period

Dyke improvement from 1885 to 1926 during the French colonial period. The French accomplished a new water control network. They introduced the step dyke profile as an alternative for the ancient dyke system.

Hanoi

city of lakes

3. city flood

CITY FLOODS Hanoi is very vulnerable to the predictions of climate change, especially to the increased probability of extreme weather events such as floods or heat waves as well as more gradual changes in temperature and precipitation [Waibel 2010: 41]. For the Red River Delta, the annual total rainfall will increase, probable up to 10 percent in 2050 [World Bank 2010: 63]. It is predicted that the return period of a 100-year event will be reduced to 20 years [World Bank 2009: 2]. Hanoiâ&#x20AC;&#x2122;s extensive dyke system has to prevent the city from inundation. Unfortunately, the problem is exacerbated by this dyke system, when heavy rain causes inner-city floods, it is impossible to drain off the water naturally towards the river. Moreover, the rapid urbanisation and land filling have changed the permeability of the ground. Together with an inefficient solid waste disposal and the low capacity of underground sewage irrigation, the city is unable to store the water [World Bank 2009: 3]. In November 2008 the city had to cope with the most extreme inner-city flood to date [Pham

Water level of the Red River during dry season

Water level of the Red River during wet season

Anh, Shannon 2009a: 7].

In contradiction with the water overload during rainy season, Vietnam contends with water shortage during dry season, with only 20-30 percent of the yearly water available [World Bank 2010: 55].

built water

Because of the dyke system and the difference in topography, the water in the city is not able to drain off naturally towards the river.

Hanoi

Map with estimated total rainfall accumulation for Vietnam from 25 October to 4 November 2008. estimated rainfall (mm) 0 60

0 25 50

100

200 km

120 180 240 300 360

City flood in November 2008 - The water rose to approximately one metre above street level, impeding daily life of the citizens.

Hanoi

city of lakes

4. city of lakes This section deals with existent practices in the usage of the water and the waterside by crossing several themes. The guidelines for this section are formed by the water bodies that are used for religion, fishing, transport, leisure, irrigation or as a residential area. Combining these water bodies with the use of their waterside, the goal is to obtain a summary of most occurring situations, which give a quick way into the reading of Hanoi as a city of lakes, and into the way citizens live with that fact nowadays.

RELIGION Religion is traditionally linked to water, and more specific to lakes. The rise in popularity of Feng Shui around the 13th century, leads to the establishing of many pagodas in and around ponds and lakes, since water was considered to be one of the 5 main elements in the geomancy theory. [Logan 2000: 24] The most famous of these pagodas lie on the West Lake and on the Hoan Kiem Lake. Both of these support a multitude of cultural and healthrelated activities on their periphery.

religion / agriculture cemetery, Yen My

religion / religion One Pillar Pagoda

West Lake One Pillar Pagoda Hoan Kiem Lake

Yen My cemetery

water

religion / street bar Tran Quoc Pagoda, West Lake

religion / exercise Turtoise Pagoda, Hoan Kiem

lake of drawing

city

dyke

3km

religion / leisure Turtoise Pagoda, Hoan Kiem

FISHING Fishing is combined with almost every kind of activity on the waterside, except when the water or waterside is being used for religious purpose.

fishing / agriculture irrigation lake, Yen My

West Lake

Yen So lake Yen My

water

fishing / residential lake, Yen So

lake of drawing g

cityy

dyke y

3km

fishing / leisure water park, West Lake

TRANSPORT Transport can only be found on the Red River, the banks of which are used for a wide variety of activities. The ferries that cross the Red River are very popular with the agricultural labourers that work on the land and need to transport their harvest to the centre of the city. Transport along the river itself consists mainly of dredging vessels that transport sand from excavation sites along the riverbanks.

transport / agriculture Red River, Bai Giua island

transport / residential Red River, Yen My

transport / market Red River ferry, Thuy Linh

Bai Giua island

Bat Trang Thuy Linh ferry Tranh Phu Yen My Van Phuc

water

transport / religion Red River, Bat Trang

transport / bar Red River ferry, Tranh Phu

lake of drawing

city

dyke

3km

transport / sand excavation Red River, Van Phuc

LEISURE Leisure activities pertaining to the water are mainly found around the lakes that lie in urban areas, like the West Lake. Typically, the lakeside is a popular location of outdoor exercise in the morning. While during the day, it is used for sports and often flanked by lots of street bars, it is in the evenings however, that the banks really burst into life, with couples on motorbikes, swan boat trips on the lake, and everyone enjoying the sunset.

leisure / agriculture row contest, Tranh Phu

leisure / leisure Truc Bach lake

West Lake Truc Bach lake

Tranh Phu

water

leisure / residential West Lake

leisure / bar West Lake

lake of drawing

city

dyke

3km

leisure / exercise West Lake

IRRIGATION

Irrigation networks are very simple but well maintained and have a wide reach on the river banks. In Yen My urban activities take place next to them.

religion / agriculture irrigation lake, Van My

Yen My Van My

water

lake of drawing

city

dyke

3km

religion / market irrigation lake, Yen My

RESIDENTIAL Residential water area is found only on the Red River, and flanked by sand excavation. The exception to this are the boats lying near the ferry that crosses the Red River and the boats on the south of Bat Trang, both flanked by agricultural activities

residential / agric agriculture lt re Red River ferry, Thuy Linh

Thuy Linh ferry Van Duc

water

lake of drawing

city

dyke

3km

residential / sand excavation Red River, Van Duc

SUMMARY

Summary of the given examples form a frame in which the most likely to occur situations can be read as a quick way into understanding how Hanoians live with their big amount of water bodies. A wide variety of use of water and activities along the waterside can be found, and the Red River still is a busy transportation arterial. Of the water bodies that have been mapped, it is noteworthy that 3 main water structures play a big role: the Hoan Kiem lake, the West Lake and the Red River. This raises the question about the role of the other water structures in daily life, as Hanoi is known as â&#x20AC;&#x2DC;city of lakesâ&#x20AC;&#x2122;. As the city is growing fast, lots of small water structures are often used as the back of the city, in means of them being

water 62

lake of drawing

city

dyke

used as an open sewage or waste dump. For this reason slums are sometimes found near polluted canals. A second trend of this swift urbanisation is that lakes nowadays are seen as potential building space as an answer to the increasing city pressure. But by filling in lakes, culture risks to disappear, since Hanoi and its citizens have always lived a strong man/water relation, as Hanoi is raised and founded in a bend of the river, and carries this fact literally in its name. As for the outside dyke area, it is remarkable that water, village and agriculture are still symbiotic, as ferries are used to cross the river, and villages are located on places with a natural higher topography.

3km

wateruse use waterside

religion

fish

transport

leisure

irrigation

residential

agriculture

residential

market

religion

street restaurant /bar

exercise

leisure

sand

Yen So

lake collector

Yen So

lake collector

1. water history This section gives a mapped overview of the water history of Yen So.

Yen So, being the southern periphery and gate for the city, is the lowest area of Hanoi. Therefore it acts as indispensable water collector for the city. As the city grew over history, the soil couldnâ&#x20AC;&#x2122;t absorb the heavy rainfall any longer, giving rise to many lakes in Yen So. This process of growing water bodies is on the hold nowadays, due to Hanoiâ&#x20AC;&#x2122;s swift growth that is claiming the lakes for building purpose, resulting in heavy water problems as there was the city flood in 2008. With the building of the Yen So Pumping Station in 2000, Yen So became the engineered heart of Hanoi, a key element in its water management.

All maps of this section are made by Tuan Pham Anh and elaborated by the authors.

LATERAL MOVES As seen in the section Landscape of Meanders on the scale of Hanoi, the same process takes place on the smaller scale of Yen So. The river has shifted back and forth over time as a result of the process of erosion, sedimentation and the building of dams and power plants upstream, both in China and Vietnam. The main shifts in flow are a result of last named factor. As hydroelectric power plants are being built upstream, less water reaches the floodplain, giving a shift to the east in this case.

A similar process occurs when looking at the history of the dykes. Since the dyke has been systematically raised, going from 4 meters up to 14 meters this present day, its top has shifted while heightening. Tracing the top of the dyke from history maps, the lateral moves of the dykes are revealed.

To protect both villages and agriculture a second dyke system has developed closer to the river. These earthen dykes are sometimes reinforced with concrete to prevent from being eroded and are fully maintained and heightened up by the villagers, levelling them between 8 and 10 metres above sea level.

1911

1935

1972

1996

2000

2010

water dyke 14m

4 km

0 100

500

1000m

Lateral moves of Red River and dyke

water in different time periods

1911

village agriculture

water dyke 14m

railway main road

During French occupation the water network was elaborated, and upstream dams like the Day Dam and the Lien Mac Sluice were built, which resulted in an important decrease of flow in the Red River [VNcold 2011]. The withdrawal of the river gave rise to several villages found on the accumulated alluvia that was left behind.

1935

250

1000m

After the Second Indochina war, the Socialist State directed villagers who lived inside dyke to create a system of earthen semi-dykes to protect both themselves and their agriculture from the river in rainy season [Pham Anh, Shannon 2009].

1972

village airport

city dyke 14m

water railway

subdyke 4-8m main road

As a result of Hanoiâ&#x20AC;&#x2122;s urban growth, lakes are being formed in the lowest area since the soil isnâ&#x20AC;&#x2122;t able to absorb the water any longer.

1996

250

1000m

As the city grew faster the lakes tended to grow with it due to the lack of impermeable soil and Yen So being the lowest area of Hanoi. Illegal settlements are being further developed on the riverbanks outside dyke.

2000

village airport

city dyke 14m

water religious place

main road sedimental sand

subdyke 4-8m highway

railway

Swift urbanisation turned Yen So into periphery, pushing farmland away to the outside dyke area. Urban pressure is claiming lakes for building ground and the Yen So pumping station, connecting lakes with river, reduced the lakes in surface. With the construction of several dams, as well inside as outside Vietnam, the flow of the Red River once again decreased, giving rise to a clear process of sedimentation: as the river withdrawals, its sediment is

left behind, and forms a natural dyke, that is sharpened by the following process of erosion. In the inner curve of the river a sediment island is created. The lakes of Yen So are given shape and the function of purification and retention lakes by the Gamuda project, making the lakes protected this way [Gamuda 2011].

2010

250

1000m

Urban pressure on lake and paddy field view from farmland to Yen So periphery

Campus for 20 000 students under construction view from Yen So periphery to Hanoi city centre

Yen So

lake collector

2. water collector This section focusses on the drainage of the To Lich basin, covering almost the entire centre of the city of Hanoi, as the Yen So pumping station and its surrounding lakes are engineered key factors in the water management of this area.

The section is part of the thesis of Thibaut Visser

Thiep River Ngu Huyen River

DONG ANH BASIN

Ha Bac River

Lien Mac Dam

NHUE BASIN LONG BIEN & GIA LAM BASIN

Nhue River

TO LICH BASIN

To Lich River

Cau Bai River

Bac Hung Hai R Thang Liet Gate Day River

5 km

To Lich Basin, which drains to Yen So

Regarding drainage, Hanoi can be divided in different water basins, either natural or planned. These basins are the TO LICH BASIN, which contains most of the central area of the city including the old centre, the Nhue River Basin, located around the Nhue river, the Long Bien and Gia Lam Basin in the north of the city and the Dong Anh Basin in the east. As Yen So is the lowest area of the To Lich Basin, the following part will only focus on the latter. The Yen So area could be called the drain of Hanoi. Since it’s the lowest area of the city, it’s the place where all the water from the To Lich Basin drains to. Because this basin covers most of the city centre, the drainage of this basin plays a major role in the flood mitigation and wastewater disposal of Hanoi. The drainage of the To Lich Basin occurs through four rivers running from the city centre to the south. Runoff water is collected by sewers and water channels, which discharge storm and sewage water into the four rivers [JICA 1995: 62]. The most prominent is the To Lich River, which starts at the West Lake at the top of the basin to the south at Thang Liet Gate, where it connects with the Nhue River. The other three rivers are the Set River, which flows into the To Lich River at Linh Dam, and the Lù River and Kim Nguu River, which are connected to the Yen So Reservoirs. The water from these rivers naturally drains into the Nhue River [HAIDEP 2007]. To limit the flooding in the city center, certain measures were proposed by HAIDEP, based on the studies done by JICA in 1995. To quantify the amount of water that has to be drained, a DESIGN FLOOD was calculated based on the major flood in 1971. This design flood is quantified as the flood after 310 mm rain in two days, which has an estimated 10 year return period. Due to the limited capacity of the Nhue River, it is not possible to drain out the design flood to the Nhue River by gravity. Small scale floods however, can still be drained by the Nhue though the maximum discharge of the To Lich to the Nhue is limited to 0.6m³/s/km² [JICA 1995: 64]. Because of the limits of natural drainage to the Nhue River, a mechanical drainage method was chosen to limit the flooding of the basin. A large pumping station was installed at the dyke, with 82

West Lake

Nhue River

TO LICH BASIN To Lich River Set River Kim Nguu River

Lu River

Linh Dam Lake

Yen So Reservoir

Thang Liet Gate

5km

Basins, pumps and rivers in Hanoiâ&#x20AC;&#x2122;s water management

Bac Hung Hai River

Red River

basin border dyke 14m water drainage / irrigation pumping station sluice

a pumping capacity of 90mÂł/s. This Yen So pumping station pumps the abundant storm water from the four rivers through the dyke into the Red River. From the study done by JICA this was the most economical solution. [JICA 1995:64]. To further limit the costs, the necessary capacity of the pumps was reduced by the integration of regulating reser voirs, the YEN SO LAKES. The reser voir consists of three lakes with a total surface of 130 ha, located in a park like area. The difference in height of the minimum and maximum water level in the lakes is 3 metres. Because storm water brings a large amount of suspended solids, the bottom sediment of the lakes has to be dredged frequently to keep the water level in its planned elevation and to ensure the reservoirs capacity. Also to limit the pollution of the Red River by these suspended solids, nutrients and bacteria, the retardation in the reservoir should be long enough to ensure sedimentation [JICA 1995: 62]. When the water level of the To Lich River is more than 4 meter, the water wonâ&#x20AC;&#x2122;t pass the Thang Liet Gate to the Nhue River [HAIDEP 2007]. Instead it flows into the Yen So reservoir to be pumped to the Red River by the pumping station later, or it flows directly to the pumping station to be pumped out to the Red River directly.

Yen So Pumping Station: view to Red River

Yen So Pumping Station: first pump

Yen So

lake collector

3. urban tissues An analysis of 7 representative urban tissues, sized 400 by 400 metres, is done in order to understand the ongoing urban transformations. The section starts with the explanation of the methodology and an introduction of the different tissues, then 5 different subsections are dealing with the following issues: the public space and structure of the city, the transformation of the area due to the urban growth, the importance of connectivity for the economical activities, the different ways of constructing the urban space and the housing typologies in relation to topography and profession.

Van Giang

Bat Trang

Phuong Thanh Tri

Yen My

Yen So

Tang Cao

Phuong Liet

A. Methodology

To completely understand the fabric of the studied area, a detailed analysis at seven representative urban tissues, sized 400 by 400 metres, is made. This method is elaborated by Caminos, Horacio, Goethert and Reinhard in 1976 [Caminos et al 1978]. Rather than trying to study the whole area, the focus on the tissues will achieve a more detailed analysis. The urban tissues are strategically chosen to get a good representation of the whole area. Factors as the transformation of the urban landscape over time and the role of the water are taken into consideration. Sample tissues both inside and outside dyke are taken. Three tissues are dealing with the changing urban fabric, two tissues concern the dyke and the last two tissues are taken in the outside dyke area.

water dyke

urban village

religious place sub dyke

main road train rail

0.5

2 km

PHUONG LIET district in the north-west is the oldest urbanized

Evolution of Yen So study area

area in Yen So area. This was the first area that the city expanded to. The lake in the tissue is derived from a meandering river but nowadays, it is cut off from the water network.

YEN SO is an urbanized village surrounded by lakes. The

transformation that this area is going through makes it an interesting site. Water bodies are disappearing and new developments are arising.

1911

In TANG CAO a whole new fully planned district is constructed. Previously it were all paddy fields, but nowadays high rise buildings are dominating the area.

1935

PHUONG THANH TRI in the north-east is one of the two

tissues that take the dyke into account. It is one of the first places where people have built outside the dyke area. The other tissue that also includes a dyke is Van Giang.

VAN GIANG village is located along the east dyke of the Red River. Here the dyke clearly determines the appearance on both sides. The buildings are only located in the inside dyke area.

1972

YEN MY situated in the floodplain area in the right bank of the Red River is a village surrounded by agriculture land. Its location is defined by the topography. 1996

BAT TRANG is also situated in the floodplain. It is located on high land and lies close to the river. Bat Trang is known for its ceramic. Previously they used the water to transport the ceramic pots to Hanoi centre. Nowadays all the goods are transported over land.

2000

B. Public Space and Structure PHOUNG LIET

The STRUCTURE of the urban fabric

shows that Phuong Liet is divided in 4 quadrants, which each grew differently. In the southeast of the tissue the remains of the original Phuong -meaning specialised community- are still visible under the form of the Pagoda. Even the lake is a remainder of what used to be a meandering river. This is the oldest part of the tissue, but it is now being demolished and rebuilded with companies and apartment buildings. Across the ring road in the north, the original tissue dated 1935, was demolished to make place

for buildings by big investors. The urban fabric on the east side is the most recent, dated 1996-2000. Along the road new buildings are located, but the inner tissue is built the same way an original Phuong is: small gates that close at night separate streets that originally belonged to different guilds. The 4 quadrants are kept together with 2 main roads. The first one is the Giai Phuong going up north to the centre of Hanoi. This road is divided in a street level road and a fly over and is flanked with a railway. The second is the ring road around Hanoi, finished in 2010.

Xe Ohm corner Xe Ohms or motorbike taxi drivers gather on the corner next to the train and the motorbike parking under the fly over of the Giai Phuong. 90

PUBLIC SPACE in Phuong Liet is located

next to roads. Connectivity means everything. Almost every public space is a source of economy as well, people gather by drinking bia hoi Ha Noi in a street bar or by having their daily pho. Both activities are often surrounded by a small market with locally grown vegetables.

Bar next to Phuong Liet Lake This polluted lake was purified in only 3 weeks as one of the preparations for the celebrations of 1000 year Hanoi[interview Nguyen, 6/9/2010]. With the reopening of the lake Phuong Liet organized one week of festivities along the lake.

water

Local market near Phuong Liet Pagoda This market is located on the main inner road of this quadrant and is a collector of social life.

built

location of drawing

pagoda

0 10

50m

Khu Tap Thei Hidden in this dense part of the tissue and accessible through a small alleyway this socialist housing block represents the Vietnamese way of building and extending as families grow. This extending is illegal, but approved in silence by the local wards [Koh 2004]. 91

PHOUNG LIET

Typical section of the Ring Road This part of the Ring Road is known for its shops that sell electricity equipment.

Typical section of the road This secondary road, parallel to the Giai Phuong knows very little traffic.

water

Village square This small open space in the dense fabric has two street restaurants and a few bars, itâ&#x20AC;&#x2122;s the place for women to gather.

built

Women cooking This small alleyway between a pagoda complex and a dense housing neighborhood is claimed for private use [KĂźrten 2008].

location of drawing

pagoda

0 10

50m

School between the Pagoda complex and the Giai Phuong

TANG CAO

The STRUCTURE of Tang Cao is recently planned and built as a consequence of the fast urban growth of Hanoi. In order to build on it, the State took back this land from the agrarians and cooperated with the partystate linked building companies such as the Housing and Urban Development Corporation (HUD) and Vinaconex. The site is topped with six apartment blocks of twelve storeys and flanked with new housing areas, containing casco’s of three storey French style villas, of which most are still empty today. This area still is under construction: more casco’s are built and the foundations and first floors for a campus of 20 000 students are already realised by Vinaconex.

As the Vietnamese building companies were able to take advantage of the rising demand for luxurious housing, Tang Cao became the land of developers, a region characterised by new high rise buildings standing in areas of decorated plots with no meaningful PUBLIC SPACE and no lively atmosphere. The rendered images of projects in the pipeline show the absolute absence of any culture-related tradition. Though, one must say that between 16 and 18hours the plots become a lively place due to the big amount of parents walking

Section through To Lich channel and new housing area This section shows the isle of the new housing area, which is not embedded in its environment. There is no relation with the To Lich channel, and what happens outside the line of building area isn’t taken into account. 94

around with their young children -but no youth is seen in this area. For the children, driven around in electric mini-cars, the geometrically decorated plots lying in between two towers and being supervised 24 by 24 hours a day by the HUD housing security guards are the Disneyland of Hanoi. The streets are typically oversized, and the pavements are halfway claimed as paid car parking, of which the guards seated under a sunshade are the only occupants of public space during working hours.

Geometrically decorated plots in between building blocks For the Moonfestival the chief of the building organises a karaoke for kids in front of the apartment block, the public space being filled with chairs. In normal weeks, during daytime this area is empty.

water

typical street section

built

location of drawing

0 10

50m

campus for 20 000 students under construction [interview Nhung and Hung, 5/9/2010]

YEN SO The STRUCTURE of Yen So can be divided into 3 parts. The first is characterised by very wide streets in a rectangular grid. This way the new part of Yen So is completely ready to welcome the car. However, today no cars are seen there and people look lost in the scale of their environment. The second part, in the southeast of the tis-

sue, is the oldest. It is built as a narrow and very dense street network with streets being only 2m wide, open sewage system included. The third area, in the northeast corner, is a strict network of small streets that are located perpendicular to the lake of Yen So and run all the way to the channel. Smaller streets connect these bigger streets with each other.

Sawing industry on a street in the rectangular grid Batminton fields are drawn on the ground.

PUBLIC SPACE in Yen So is created as a consequence of the width of the streets. This way people meet on the pavement or even paint a badminton court on the concrete. Though there are a few efforts, the public space is badly maintained and much polluted. In the narrowest quarter below, people live next to the open sewage.

Section through market The market is located near the lake, however it is not making any relation with it. The streets surrounding the market are filled with saleswomen.

water

Narrow street with open sewage

Busy road filled with shops

built

location of drawing

0 10

50m

Secondary road with shops

YEN SO

Street perpendicular to lake In this area streets run from lake to channel.

back of shop Embedded in the tissue, the back of the shops form hidden spaces of green. A small vegetable garden provide both shop as inhabitants.

water

bar next to lake On this side the lake has a quay with trees. In its shadow bars and few fishermen create the atmosphere.

built

location of drawing

0 10

50m

narrow path on lake This narrow road divides the lake of Yen So in two parts. On the earthen path a fisher pier is installed.

YEN MY The STRUCTURE of Yen My is dominated by topography. Yen My is located on the right river bank, on a sedimental isle of 9 to 10m height. Since this level isnâ&#x20AC;&#x2122;t enough to prevent flood risk, the inhabitants started to highten up houses and to pave their streets with the help of the government in 2005. Furthermore the village structure is based on agriculture. There are 2 main streets

that run parallel to the water and a series of secondary streets that run perpendicular to them. The houses are spread around the isle and connected by a dendritic street network attached to these secondary streets. Each house has a domain or garden on which bananas and vegetables are grown on a small scale. These private gardens are typically fenced with 1,5m high walls.

The PUBLIC SPACE of Yen My is sided on the east, on a small road between the village and the water. This road is a collection of bars, small groceries and a flourishing village market on the main crossway halfway across the village.

Section through main street Yen My is surrounded by lower farmland. On its main road a market is situated next to water that is used for irrigation purpose.

100

water

Section through main street As the main street approaches the crossing, the street gets smaller and is flanked by tea corners next to the water.

built

location of drawing

0 10

50m

Inner vegetable garden

101

YEN MY

House heightened up by concrete roads Since natural topography was the only flood prevention Yen My had, houses and streets are recently heightened up with concrete, making the streets a level in between natural topography and house [interview Chien, 24/8/10] 102

House heightened up by concrete roads

water

Tailor along the main street

built

location of drawing

0 10

50m

Shop in inner street Besides a vegetable inner garden, some villagers have a minishop located on secondary streets.

103

PHOUNG THANH TRI The STRUCTURE of Phuong Thanh Tri is a patchwork of lots of functions. 3 schools are fitted alongside big factories, wealthy but also poor houses, and some student housing with very narrow inner courts. There is no logic to be found, except that everything is connected to the dyke. Though lying 5m higher on the left and 3m higher on the right, the dyke does not behave like a border.

The PUBLIC SPACE much like Phoung Liet is be found near the roads. Inner streets of the tissue form busy village markets and the 3 schools in this area make the streets very lively at rush hour.

Market on main street This main street, though lying much lower than the dyke, is in direct connection with it and has a busy street life.

104

Playground between school and dyke The playground is used for morning exercise and after school gathering. Once school is finished children run from the school gate over the dyke verge to the bus stop on top of the dyke.

dyke

Bus stop on top of the dyke This section gives the difference in heights on both sides of the dyke, the right side of the section being the outside dyke area, close to the Red River. Though the difference in height being remarkable, the people of Phuong Thanh Tri form a close community [Hang, 23/9/2010].

built

location of drawing

0 10

50m

Narrow street parallel to dyke Steps are running from the top of the dyke towards the local groceries.

105

PHOUNG THANH TRI

Street taken in for a wedding party

106

Narrow student housing with inner court

Local use of dyke for laundry Along the dyke some other local uses are found such as small vegetable fields.

dyke

School in dense tissue

built

Market near school and industry

location of drawing

0 10

50m

Back of industry next to wealthy villa

107

BAT TRANG

Lying outside dyke on a mound of accumulated alluvia, Bat Trangs STRUCTURE has its origins in the 15th century, where the village was the only place of refuge in an area with no citadel nor dense forest [Fanchette, Stedman 2010: 109]. Therefore, to deter intruders, an incredible maze of alleyways of maximum 1,2 meters width was created [Fanchette, Stedman 2010: 112]. Over centu-

ries this maze remained the beating heart of the ceramic village: behind each door or gate, in hidden workshops, clay and water were merged to form art. In the small alleyways only the walls betray the ceramic secret: charcoal patties made of coal dust are stuck up to dry on the village walls to keep the handicraft kilns burning [Fanchette, Stedman 2010: 112].

PUBLIC SPACE is rare in Bat Trang. Due

to the festivities of 1000 years Hanoi, the first public space was created as an oversized reality. A second place that is more meaningful is the square in front of the Pagoda that opens up to the Red River and the skyline of Hanoi. Finally, the market of Bat Trang is a flourishing business that attracts lots of tourists, though this is not completely public since its gates close at night.

Viewpoint in front of pagoda On top of the mound of accumulated alluvia, the square in front of the pagoda gives a wide view on Hanoi preceded by the Red River. This place is the only place in the Yen So case study area where a view from height this close to the river can be enjoyed. The slope of the mound was reinforced with concrete in order to resist the process of erosion. 108

water

Typical maze alleyway A saying dear to the inhabitants of Bat Trang summarizes the situation: â&#x20AC;&#x2DC;Live in cramped conditions, die on borrowed landâ&#x20AC;&#x2122;

built

location of drawing

0 10

50m

Bat Trang market Point of attraction for tourists.

[Fanchette, Stedman 2010: 111]. 109

BAT TRANG

1000 years Hanoi square This square used to be an area of poor housing. It was demolished in favour of an oversized public space with cardboard facades and fake buildings to celebrate the 1000 years of Hanoi.

110

water

Ceramic workshop hidden in alleyway Most of these workshops are heightened up in the structure of the maze as an extra prevention to flood risk.

built

location of drawing

0 10

50m

Tourist workshop Near the market some workshops where tourists can make their own ceramics are opened. They are located along the main roads of the maze.

111

VAN GIANG The STRUCTURE of the Van Giang fabric is mainly formed by the ornamental tree gardens. The gardens are surrounded with a 1,5m wall or fence and all are linked to a small path, connected to a bigger street, which leads to the dyke.

PUBLIC SPACE isnâ&#x20AC;&#x2122;t consciously created in Van Giang. People meet in the streets and children play on the dyke flanks or near the ornamental tree gardens. The exception to this are the steps near the lake where women come to wash rice or to dry cane.

Van Giang lake This lake lies close to the dyke and gathers several important functions for the village. In the north a pagoda lies next to it, followed by some farms, and the steps which form a public space for social gathering and women maintaining the household. 112

water

Typical ornamental tree garden The pots in which these trees grow are made in workshops both in Van Giang and Bat Trang. The ones made in Van Giang are commonly put on the dyke verge to dry in the sun.

built

dyke

location of drawing

0 10

50m

Typical flower garden

113

C. Urban Growth

2000

2010

PHUONG THANH TRI Building outside the dyke area In 2000 most of the people lived inside the dyke. Houses were situated next to the main roads. However in 2009 the situation changed. The outside dyke area had become a dense district. The lake was filled with sand and new buildings were built on top of it.

150M

water built

dyke road

The last 10 years a remarkable process is changing the landscape from a village based tissue towards a city tissue. In this chapter the most important changes are pointed out by examining the evolution of three tissues, Phuong Thanh Tri, Yen So and Phuong Liet. PHUONG THANH TRI is characterized by the dyke who splits the village in two. Previously the location of the dyke had a remarkable role in the housing development. Today in Phuong Thanh Tri, the dyke location is less important because the outside dyke area is situated very high, between 9 and 10 metres above sea level. This makes the area not so vulnerable for flooding. Through the years the city sprawl arrived at Phuong Thanh Tri, the building expansion happened simultaneously at both sides of the dyke. There was no plan behind the spatial placement of the houses. In the outside dyke area, the houses are placed at random with empty green spaces between one another. These spots seem to be waiting to get allocated as well. In the inside dyke area, the few water bodies were filled with sand to construct the buildings on top of it.

new houses built in the outside dyke area.

Criss-cross placing of the houses of Phuong Thanh Tri in the outside dyke area in 2010. The picture is facing towards the city centre of Hanoi with the Red River behind the photographer. 115

2000

2010

YEN SO Disappearing of lakes In 2000 a large lake was present in the middle of the village Yen So. During the next years, land filling created more space for buildings and decreased the amount of water resulting in a whole new district in the middle of the village.

150M

water built

road

Yen So tissue water ring road dyke Masterplan 2020 - Ring Roads circling around the centre of Hanoi

YEN SO is a village surrounded by several lakes. The current Vietnamese master plan structures the city with a network of ring roads circling around the centre of Hanoi. The third ring road passes near Yen So which makes the village a strategic area for the city. Developers have invested in the village, farm land was bought and lakes were filled with land.

5 km

housing block appeared. The main accent was set on the road network to create place for the cars. Less attention was given to the water. The water bodies became the backside of the village where garbage was regularly dumped.

In 2000 the centre of the village was characterized by a large lake, but after building activities started, parts of it were filled with sand and new housing developments took place. A whole new 117

The lakes as garbage collector.

118

modern super market new commercial complex

traditional market water Different market typologies in the surrounding of Yen So

At the moment another part of the lake has been transformed into a construction site. A new commercial centre is planned to arise in Yen So. The project is confirmed by the City Peopleâ&#x20AC;&#x2122;s Committee of Hanoi and the developer has received a land use certificate to use the farmland. The centre will contain a big super market, electronic equipment shops and a cafeteria at the top floor [information panel at construction site].

150M

market, METRO. In the METRO, only people with a member card are allowed to do their shopping. Together with the new developments, Yen So is ready to become a highly visited commercial district of the suburbs of Hanoi.

Nowadays Yen So already has a covered market, based on the traditional Vietnamese market, and a big super 119

2000

2010

PHUONG LIET Building on the empty spaces In 2000 the water had a visual connection with the Communal House of Phuong Liet., but because of the urban growth, the empty space next to the water was built on. The urban growth was accompanied by big infrastructural works. Houses were destroyed to make room for new roads.

150M

water built

road train rail

Sketch of the situation in 1945. The Communal house was situated next to the water body.

PHUONG LIET is one of the oldest urbanized areas of the region in the south of Hanoi. In 2000 it was already a very dense area. The space near the lake in the south was the only open space left. The open space preserved the connection of the Communal House with the water. A communal house is one of the features of every village and hamlet in Vietnam. It is the centre of the community life. Ceremonies, traditional festivities and discussions between villagers take place in the communal house. The location in the village is determined by the rules of geomancy. It must be located close to a river or lake and near a busy crossroad [Quoc Chinh 1998: 25]. The old sketch above shows the situation in 1945. You can see that the communal house was originally located next to the lake.

Nowadays due to the urban growth this empty space is being built on. The connection between the Communal House and the water is broken.

121

The exit lane of Truong Chinh with Giai Phong is one of the chances in the urban fabric of Phuong Liet in the last ten years.

122

Destruction of buildings to make room for a new road.

In consequence of the increasing use of motorised vehicles, the government implemented some big infrastructural works in Hanoi. In the Phuong Liet district an extra exit lane was needed to facilitate the traffic flow. To realize the project a whole housing block had to be pulled down. Since the government owned all the land, it was relatively easy to ‘expropriate’ the residents (since they didn’t own the land) and to give them another piece of land to live on [Kammeier et al. 2002: 375]. The destruction of the buildings and the construction of the road started in 2004. Only the exact space needed for the road had been stripped down. If a house was only partly situated on the selected

area, only that part was destroyed. It was possible for residents to stay in the piece left of their house but then they had to construct a new façade. This process of urban growth changed the performance of the urban fabric by cutting in the existing structure and filling in the open spaces. Combined it led to a new way of living with or without water and to a new infrastructure network adjusted to the new needs. It was followed by other rules than geomancy and feng shui.

123

D. Connectivity The location of public and commercial activities has a relationship with the hierarchy of the streets. The tissues Phuong Thanh Tri, Yen So and Phuong Liet express this relation. ACCESSIBILITY is very important for the economic activities. Almost all the shops are situated at principal roads. They mainly consist of little shops located one after the other. In general, principal roads in Vietnam are used as longitudinal markets. The ground floor of traditional houses changes dramatically over time. At night access from the street is obstructed and the room is generally used as garage for the motorbikes. In the morning the door or gate is opened and the room is set up as a shop where the residents sell vegetables or self-made tools or they offer Vietnamese breakfast, Pho. At noon the residents eat in the room and take a nap. In the afternoon, people come back from work and buy the things they need in the shops. In the evening the shop closes and the room is changed into the living room and later on back into the garage for the motorbikes [Khawatmi 2001]. Nowadays a new type of shop is arising: the so-called modern super market. Big complexes are being built. As mentioned in the section of Urban Growth, Yen So is starting to become a highly visited commercial district with the already existing Metro mall and a new commercial centre in the future. It is possible that these malls will dominate the shop streets. Remarkable is that the dyke in Phuong Thanh Tri doesnâ&#x20AC;&#x2122;t play an important role in the commercial activities although the fact that the dyke is the main road. The markets are not situated on the dyke, but on the parallel roads. This is because the dyke works on a bigger scale and the shops are more focussed on the local needs. Little 124

restaurants and candy shops are situated in the neighbourhood of the school. When the kids finish school they buy their food in these shops. A different approach is used for the public buildings. They are not situated along the main roads but more in the back streets or along public plazas. We could make a cautious conclusion that these building donâ&#x20AC;&#x2122;t need to be extremely visible. The visitors will come anyway. The customers are more regular. However this could also be because there is no place left along the main roads. The situation along a main road is very wanted by the shop-owners. Remarkable is the fact the role of the water bodies is minimal. The location of the shop is completely road-based. The water is neglected.

YEN SO The principal streets are occupied by small market stalls. People on motorbikes stop in front of the stands and buy the goods they need. Some of the hawkers are established in the covered market.

150M

shop market

bar administration

water road

Section AA trhough shopping street in Yen So

PHUONG THANH TRI Little houses consisting of only floor sell their goods to the local inhabitants. They are situated at the roads next to the dyke. The ground level of some shops in the outside dyke area is 0.5 metres higher than the road level to resist flooding. B

126

150M

shop school

industry dyke

road

Section BB through shopping street next to the dyke.

PHUONG LIET Small high townhouses with a shop on the ground floor form a stone wall along the main roads of Phuong Liet. Large billboards call for attention of the passing drivers.

150M

shop dentist

karaoke bar

school religious place

water road

Section CC through important main street connecting 127 Hanoi with its southern region.

formal

SUMMARY - SHOP Many types of shops exist. There is a remarkable difference between the informal and the formal shops. As the informal shops are more flexible and movable, the formal shops are much bigger and mostly located in a building.

big

SUMMARY - STREET There is a large variety of street typologies. The bigger streets are more populated, while deeper into the housing district, streets become smaller and fewer activities take place. The hierarchy of the streets gives an overview of the different atmospheres.

informal

small

129

E. Difference in planning Looking to the studied area of Yen So different urban fabrics can be found. The

UNPLANNED,

SEMI-PLANNED

and PLANNED fabrics are altered in the landscape. The UNPLANNED parts are mostly the oldest urbanised parts. They are formed following the traditional way of building in Hanoi. The street pattern is formed by the positions of the houses. Newer urbanised parts are more influenced by the western architecture and way of constructing. First a street pattern is devised and put into place. Later on the houses can be built on the plots between the streets. This SEMI-PLANNED fabric is widely implemented. Some investors design the streets as well as the buildings what leads to a fully new PLANNED district. The tissues Phuong Liet, Yen So and Cang Cao are examples of the three different structures.

130

The UNPLANNED fabric of Phuong Liet became denser and denser over the years. No strict plan was followed. HOUSES were constructed without taking into account the neighbours’ privacy or the possibility to get some direct light inside their houses. This kind of fabric is formed following the traditional way of building in Vietnam. Previously, each family or guild was organised as a ham. A ham is equivalent of a small village in rural area where all the villagers practised the same craft. Over time the city became denser and the hams were interwoven. The densification led to the typical tube houses. Small long houses with a width between 2 and 4 metres and a length of more than 20 metres were built perpendicular to the streets. The narrowness of the façades could be explained by the fact that feudal

PHUONG LIET

100

200 m

built road

water train rail

laws taxed the merchants according to the width of their façades [Quoc Chinh 1998: 15].

The STREET PATTERN is evolved of this ham structure. The width of the street narrows according to the traffic that passes by. The small streets split in even smaller streets until it is almost impossible to drive on these streets with a motorbike. The WATER body in the south-west has recently been hardened with concrete. Nowadays it has a planned waterside. During the day, little bars are put into place next to the water. This is in sharp contrast with the polluted and neglected waterside of the Lu River just outside of the chosen site, passing the lake in the south. 131

After a part of the lake was filled with sand, a whole new SEMI-PLANNED district was constructed in Yen So. First the streets were constructed; afterwards the ground was allocated and sold to families. The STREET PATTERN is a rectangular grid with wide streets. It is designed for car traffic that will take place in the future.

YEN SO

House after house was built. It seems that the inhabitants have constructed their HOUSES following a general building policy. The houses donâ&#x20AC;&#x2122;t look the same but the size and orientation towards the street are almost equal. However the decoration and details are chosen by their own taste. The WATER body in the east is fully designed. A stone walking path lies next to 132

100

200 m

built road

water

the lake, there is a stair to reach the water line and trees are planted in a row marking the space. This lake is in strong contrast with the remaining water bodies. These are planned to disappear thus no design is made. As a consequence the people use the waterside of these neglected lakes to dump there garbage.

Tang Cao is an example of the new fully

PLANNED urban areas. It is made

by the state-controlled housing and urban development corporation HUD [K端rten 2008: 7]. They create new private and public spaces within middle-class residential areas. TANG CAO

The STREETs are dimensioned for car traffic. They are wide lanes with a large foot path and trees on both sides. The district is only connected to the general street network with two roads, of which only one is hardened nowadays. The other one is full of holes and mud. This has the consequence that only inhabitants are using the streets and public spaces.

Cao. The first typology is the same as the houses built in Yen So. The main structure is fixed but the rest can be chosen by the inhabitants. The other typology are high rise buildings of 15 floors with an average of 8 apartments on one floor. The planning company has neglected the WATER bodies in the area. Either a highway separates the ward with the water, or a fence and plants block the view on the canal. Since all the waste water of Hanoi is flowing through this canal, it would not upgrade the district.

Two types of HOUSES are built in Tang 0

100

200 m

built road

water

133

Some criticism can be made when comparing the three fabrics. In the UNPLANNED areas, the densification process has captured the hamlets and made them less liveable. The open courtyards which provided good ventilation conditions and enough natural light are overbuilt to create more rooms. The streets are not able to cope with the increasing streams of traffic resulting in more and more traffic jams. Open spaces and water bodies are filled up resulting in less and less public space and meeting places. However the traditional way of the shop house is preserved. The people use their houses in the way it is designed and feel at home.

Strong densification of the old districts leads to close 134 to each other built houses.

In the fully PLANNED fabric the streets are provided for the increasing traffic flows and big green spaces are constructed to offer enough open space for public activities. A problem is that the design of these places is not based on the traditional Vietnamese architecture. Inspiration is gotten from the western cities which sometimes results in the wrong use by the Vietnamese people or the non-use of it. The high rise buildings don’t give the possibility for the Vietnamese to run an establishment and don’t make it possible to adjust the house to the changing family situations. It is not very compatible with the lifestyle of the residents. The SEMI-PLANNED fabrics are also no good answer to the changing family conditions. A general structure is

generated and built without thinking of the family situations over time. The general structure is quite large so it isn’t possible to build a small house. It also isn’t possible to expand the house to fit all family members. The growth of the district is also not enough coordinated. Sometimes, the building process remains unfinished a long time due to a money or time shortage of a family, which results in a park of empty carcasses with occasionally a finished house. Living in these areas is like living on a big construction site. In conclusion, new ways of dealing with new urban tissues need to be developed. Lessons need to be taken into consideration from the Vietnamese way of living and their use of the house and public

Two women playing badminton in the planned green area which is only designed to walk through. They have to improvise the borders of their playing ground.

spaces in relation to water. These need to be integrated with the challenges of the modern city such as increasing traffic flows. Instead of excluding the water inside the city, the water network of lakes could play the structuring role of the fabric with attention to its value for the public space and flood prevention.

Due to money or time shortage families are living in their unfinished house in an incompleted neigbourhood.

135

Although the picture seems to be taken in France, these houses are constructed in the west suburb of Hanoi. 136

More and more Vietnamese people have bought a motorbike. Nowadays the amount of cars being sold is also increasing. This process will end in roads that are beyond the maximum of their capacity. 138

F. Housing, Topography and Profession

YEN MY

BAT TRANG

topography 0 3 4 5 6 7 8 9 10 11 12 13 m

dyke water

PHUONG THANH TRI

built

VAN GIANG

100

200 m

topography

0.5

2 km

0 3 4 5 6 7 8 9 10 11 12 13 m

The two tissues situated in the outside dyke area and the two tissues concerning the dyke are pointed out to look at the creation of different housing typologies.

246]. Despite the vulnerability to flooding,

the advantages of the location such as low land price and open space are playing a bigger role in the decision to settle there [Kobayashi et al 2010: 104].

The typology of the housing in these tissues is examined for several factors: the topography, the vulnerability for floods and the profession of the inhabitants. The TOPOGRAPHY of the region of Hanoi is formed by the Red River flow. The alluvial process by the river has raised the level of water above the elevation of the city itself. Dykes were constructed to protect the city. Earlier the people settled in the area protected by the dykes. Only some traditional villages were situated at the higher levels in the outside dyke area. However since the city is expanding rapidly, new settlements are arising in the outside dyke area. It knew a population growth of 1.6 during 2000-2004 [Kobayashi et al 2007:

The population in this area has rapidly increased starting from the year 1975 when 33’475 people where living in the outside dyke area to the amount of 160’602 residents in 2004 [HAIDEP 2007: 135]. This tendency is an important problem in terms of flood management because the settlements in the floodplain area of the Red River decrease the permeable soil and obstruct the river flow [Kobayashi et al 2010: 104].

It is the government who has encouraged the people to live there by starting to build in the outside dyke area. In 1954, the new Vietnamese government established new accommodation for the government’s 141

During the flood of 1926, the whole floodplain was flooded. Because of its high location, Bat Trang was spared from flooding.. The water level reached the height of 11.95 metres above sea level which was higher than the actual size of the dykes. At several points the dyke wasnâ&#x20AC;&#x2122;t able to keep the water out of the city [Gauthier 1930: 16].

142

staff and new inhabitants of Hanoi in the floodplain areas next to the city centre. They continued building until the flood of 1971. After this flood event no formal housing programs have occurred in the floodplain area. However the informal housing market didn’t stop. In the 1980’s and 90’s the Hanoi Master Plan for the year 2010 and later the one for the year 2020 both placed the centre of the city in such a way that the outside dyke area became an interesting space close to the centre (the centre of Master plan 2010 was West Lake, the centre of Master plan 2020 located the Red River as the central axe of the city) [Kobayashi et al 2010: 105]. Since the flood of 1971, the flood management policy has changed its policy from flood response to flood prevention with special attention to the strengthening of the dykes. The dykes needed to be protected from the illegal constructions. To stop building in the outside dyke area, the CPC (Hanoi City People’s Committee) started the “Civilized Way of Life and New Cultural Family” campaign to make people aware of the flood risk in these areas. However illegal constructions continued to appear. Since 1983, the CPC changed its policy and started to implement legal regulations. In the next 20 years, almost 20 different decrees were issued by different authorities. There was a lot of confusion and misunderstanding of the regulations. For example one of the first decisions legitimized the existing buildings, which gave the resident the idea that in the end the state would legitimize all the offenders. In 1995 as part of the disaster management policy of Hanoi, the CPC, in cooperation with the Ministry of Water Resources, demolished all the constructions situated near both sides of the dyke. However this action only had an impact within the dyke protection areas and not within the whole floodplain of the Red River since the main consideration was the safety of the dyke

These ineffective construction regulations and a weak control policy are the result of the disagreement of policy goals of the urban development and disaster management. Together with the low perception of catastrophic flood risk among the residents, it demonstrates the lack of knowledge about flood. The risk perception is an important factor to understand the motives of the people living in the outside dyke area. A structured survey done by Hoang Vinh Hung, Rajib Shaw and Masami Kobayashi from the Graduate School of Global Environmental Studies of Kyoto University investigated the community perception of catastrophic flood risk. In general they could conclude that there is a low perception of catastrophic flood risk. Almost half of the respondents didn’t think that a flood as big as in 1971 (flood period of 100 year) would occur within next 70 years. Only 8.2 per cent of the respondents indicated flood as a major disadvantage to live in this area [Kobayashi et al 2007].

To stop the continuation of building in the outside dyke area, the government has to work better in a distinct way in order to avoid misunderstandings. The knowledge about catastrophic flood also has to be improved to change the perception of the residents and to make them better prepared for the next flood event. The most important goal of the flood management policy is to decrease the amount of constructions in the outside dyke area because these constructions are intensifying the vulnerability for flooding of Hanoi.

[Kobayashi et al 2010: 106]. 143

Yen My

Bat Tr Trang ang

Phuong Phu ong Thanh Thanh Tri Tr i

Van Giang Giang 0 10 20

50 m

place where section is made

Phuong Thanh Tri

Bat Trang

Yen My Van Giang

height above sealevel

0 0.5 1

2 km

0 3 4 5 6 7 8 9 10 11 12 13 m

Concerning the TISSUES, two situations are pointed out: the villages in the outside dyke area and the housing constructed close to the dyke. The tissues of YEN MY and BAT TRANG are dealing with the traditional villages in the outside dyke area. The houses are situated in areas more than 9 metres above sea level. This protects them from annual flooding. The citizens of Yen My are cultivating the fields around the village. The periodical floods make the ground very valuable for agriculture. During wet season most of the fields are inundated and the citizens stay home, doing some small handicraft such as sewing raincoats. Previously, the farmers knew when a flood would come and they had time to take the harvest inside. With the construction of the Hnghe Hanizu Yizu Dam in China upstream, the floods occur unpredictably. The other village is Bat Trang, which is one of the oldest settlements in the area. It has a long history of making pottery. The area is extremely elevated by the sediments of the Red River since the river is turning at this area. The location next to the river makes it possible to transport the ceramics

to the city centre in boats, but nowadays, car traffic has replaced the boats. In the two cases, the villagers have learned to live with the river conditions. Instead of fighting against it they use the characteristics of the floodplain area of the river for their own advantages. The other situation is the area around the dyke. In PHUONG THANH TRI, the ground in the floodplain is never situated less than 10 metres above sea level. Because of its high level, houses are constructed in the outside dyke area. They are protected by the natural conditions of the land. The area inside the dykes is lower than the outside dyke area, but the dyke, with a height of 14 metres, protects it from flooding. Here the dyke is more important than the topography because of the vulnerability for flooding. VAN GIANG village is very low located between 0 and 6 metres above sea level. Without the dyke the area would suffer repeatedly from floods. This is the reason why no houses are situated at the other side of the dyke in the floodplain since the area is located at the same level. 145

To summarize, the vulnerability of the buildings can be determined by different factors and it strongly depends on the location. The placement of the buildings in or outside the dyke area is a first important factor for the safety of the area. If the buildings are located in the outside dyke area, the topography is the major factor that defines the vulnerability. In the areas inside the dyke the topography is of less importance and the vulnerability depends on the strength of the dykes and of the drainage quality of the city. Since the sediments of the river raise the river bed, only relying on the topography will not be sufficient to secure safety. The location of the buildings in combination with the profession of the residents define the TYPOLOGY of the houses. In BAT TRANG a large part of the house is used as storage for the pottery to dry. Most of them have a working space inside the

House in Phuong Thanh Tri 146

house to make the pottery. The living spaces are more into the back of the house, connected with the atelier. On the faรงade, coals are placed to dry so they can be used afterwards for pottery making. The farmers of YEN MY live in different housing typologies. Some have simple wooden constructions of one floor; others live in more majestic houses with one or two floors. The ground floor is situated one metre above street level for flood prevention. The water and fields are never far away from the houses. In PHUONG THANH TRI, which lies in the tissue the closest to the city, the houses are more like city houses. The small high row houses are placed next to each other. The ground floor is set up as a shop and big advertisement panels with colourful texts dominate the front faรงade.

VAN GIANG is the tissue the furthest away from the city centre. Large open spaces alternate with the buildings, there is no lack of space. Big houses are dispersed in the area. They all have a garden where ornamental trees are cultivated. The houses are majestic and remarkable. In conclusion, generally the typologies in the outside dyke area have a ground floor which is approximately one metre elevated from the land for flood prevention. Further away from the city centre, the land price is cheaper and therefore more money is left to use for the building itself. The density is also much lower, which results in big detached houses. In brief, it is possible to say that generally the typologies are linked with the profession of the residents and with the site where the construction is built.

House in Van Giang

Phuong Thanh Tri

Bat Trang

Yen My Van Giang

urban district farmer village

House in Yen My

pottery village ornamental tree village

0 0.5 1

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House in Bat Trang 147

Red River floodplain

Red River Floodplain

1. sections As the river carries a vast amount of sediments, the topography of the floodplain is redrawn each time the river floods. Due to this alluvial process, the floodplain, limited by the dykes, lies higher than the city itself. By making several sections in the floodplain, the main characteristics of this area are pointed out.

METHODOLOGY Several SECTIONS were made in the floodplain of the Red River. To get a general view of the floodplain a section was made every 500m. Besides this distance the place of the sections was completely arbitrary. Afterwards the sections were completed with the help of a topographical map obtained from GIS information. To be able to show the features of the floodplain, a shift in scale is made between the horizontal and the vertical dimensions, since the floodplain at its widest has a width of approximately 8 km and the elevations have â&#x20AC;&#x2DC;onlyâ&#x20AC;&#x2122; a difference of 16 metres. Therefore, A scale of 1: 500 is used for the vertical dimensions and a scale of 1: 10 000 for the horizontal dimensions.

152

A B C D E F G H I J K L M N O P Q 0 0.1

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Section A and B show most noticeable the difference in height between the in- and outside dyke area.

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water dyke

building envelope

155

Located on a mound d of accumulated alluvia, stands Bat Trang, one ne of the oldest villages in the floodplain. Since a long time, the alluvial process has raised up the east bank. However, nowadays, ys, due to the bend in the river, the main stream passes the east bank with great velocity, ocity, increasing the risk of land erosion. To protect Bat Trang from the forces of the river, iver, the river bank has been made of concrete. rete. On the west bank, bank ba nk,, a su subd subdyke bdyk ykee of approximately 8 me metr metres tres es hhig high ighh is implemented. It protects rot otec ects ts tthe he aagr agricultural gric icul ultu tura rall fields from the seasonal son onal al flfluuuctuation ctua ct uati tion on of of th thee Red River.

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water dyke

building envelope

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On the the following ffol ollo lowi wing ng ssec section, ecti tion on,, th thee di diff difference ffer eren ence ce in in thee ea th east st aand nd w wes west estt dy dyke ke iiss vi visi visible. sibl ble. e. T The he w wes west estt dyke dy ke is is executed exec ex ecut uted ed aass a st step ep d dyk dyke, yke, e, iint introduced ntro rodu duce ced d by tthe he FFre French. renc nch. h. It It de desc descends scen ends ds sslo slowly lowl wlyy to towa towards ward rdss thee ri th rive river. ver.r. T The he eeas east astt dy dyke ke iiss mu much ch sste steeper. teep eper err. Most Mo st o off th thee ro road roads adss go goin going ingg fr from om tthe he eeas east astt dyke dy ke iint into nto o th thee floo oodp oodplain dpla lain in aare re ttoo oo sste steep teep ep tto o be d dri driven rive venn on b byy ca car.r.

industrial activities In section ssec ecti tion on H H,, in indu dust stri rial al aact ctiv ivit itie iess ar aree located river. loca lo cate ted d ne next xt tto o the the west west bank ban b ankk of tthe he rriv iver err. transformed Thee ba Th bank nk iiss tr tran ansf sfor orme med d in into to concrete ccon oncr cret etee quays ships quay qu ayss which whic wh ichh make make it it possible poss po ssib ible le ffor or tthe he sshi hips pss to berth. ber erth th.. G

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water dyke

building envelope

As mentioned before, the topography of the floodplain is created by the alluvial process of the river. The closer one comes to the dyke the lower the ground level is which results in the formation of small lakes next to the dyke. It is possible that the ground near the dyke is used to make the dyke itself which explains its low situation. Nowadays, these low areas are mostly used to cultivate rice.

Section I cuts through the pumping station of Yen So. From the pumping station, a canal starts towards the river, creating a deep incision in the landscape (as seen in section J), to overcome the elevation barrier of the land.

A link is found between the topography and the location of the villages inside the floodplain. For instance, in section K, the village Yen My, located on the west bank of the floodplain, is built on ground that is higher than the agricultural fields surrounding it.

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water dyke

building envelope

The following sections cross the floodplain plai pl ainn at its widest. This area gives space to a ri rich ch variety of agricultural activities.

On the east bank, the subdyke is located ated at ed far inwards the floodplain. This is attributed uted ut ed to the fact that previously, the river fleew w more eastnorth than it does today. Apart from the subdyke, other roadss ar aree situated in the floodplain. Most of th thee roads are approximately half a metre tto oa metre higher than the fields they connect nec ectt with. The roads are mostly combined with with small irrigation channels at both sides es to drain the rainwater from the road and d th thee fields.

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water dyke

building envelope

These sections are located where the the river makes a 90 degree turn towards tthe he O east; afterwards it bends again to continue nuee nu direction south. In earlier times, the rriver iver iv er has raised the west bank due to th thee sedimentary deposit, the village, Van Phuc, huc uc,, is established on the elevated ground. und. un d. Nowadays, the village is exposed to th thee strength of the huge volume of water tthat hatt ha surge down towards the village before for oree bending off. Some concrete banks aare re constructed to diminish the destruction tio ionn process. At the west bank in section P, sand and an d excavation activities are taken place. ace. ac e. During dry season the level of the water ater at er is remarkable lower than in rainy season. son on.. Large sand banks are appearing creating atin at ingg islands in the river or sand dunes along tthe he river bank.

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water dyke

building envelope

Red River Floodplain

2. agriculture The main area of the floodplain is used for agriculture. It plays an important role for the villagers living in the floodplain. The harvest is also of importance for the citizens, since about 70 percent of the vegetable production for Hanoi is produced in the suburban district, including the floodplain of Yen So. In this section a research is done into the importance of the conservation of large agricultural areas in the vicinity of the city centre.

168

Cultivation of vegetables in the floodplain

It is remarkable that LARGE RGE AGRICULTURAL AREAS still existt iinn close vicinity of a booming city. Th Thee extraordinary growth of Hanoi in tthe he last decennium has decreased the aarea reaa re of agricultural land, but in spite of th this this, is,, olee ol agriculture still plays an important rrole ithh it for the city. It supplies the townsman w with nd it valuable food security and income and ns to allows the poorest part of the citizens [van an provide in their own nutritional intake [v den Berg et al 2003: 37; Binns et al 2010: 1]. ].

THAI NGUYEN prov.

Soc Son

VINH PHUC prov.

Dong Anh

Another positive effect of URBAN BAN AGRICULTURE is that the increasee of Tu Liem food supplies generally decreases th thee urban food prices. The urban agriculture, ture tu re,, Gia Lam if properly planned and managed we well well, ll,, contributes towards the development nt of safe and non-polluted environments. It aalso lso ls o Thanh Tri has an impact on waste management nt in HA THAY prov. HUNG YEN prov. cities, since waste that is properly treated, ated at ed,, can be applied to crops safely. Some plants lant la ntss can be used in the purification process ss of city districts 0 2 5 10 km wastewater. The urban agriculture has an water indirect positive impact on energy use. Location of the five suburban districts The distance between the production and consumption area is very short, which reduces energy expenditure on refrigeration, transport and storage [Binns et al 2010: 2]. However cautiousness is required since the closeness of the city can affect the healthiness of the nutrition because of untreated waste and other pollutants present in water courses, on land or in the air. The pollution can lead to high heavy metal and toxin levels in agricultural products [Binns et al 2010: 2]. In HANOI the production of the suburban districts provides between 62 and 80 percent of vegetable production and approximately half of the fishing for the inhabitants of Hanoi, which underlines the importance of the agriculture near the city [van den Berg et al 2003: 37]. The vicinity of the city also increases the demand for several food products such as pork, vegetables, fruit and fish. This tendency leads to higher prices, which makes food production more profitable. Farmers respond to the increasing demand and start cultivating the most wanted products to make more profit [van den Berg et al 2003: 37]. A study done by Jansen et al [Jansen, H.P.G., Midmore D.J. in van den Berg et al 2003: 41] has investigated the net return per year for rice and vegetables in Ho Chi Minh City. The net return per year for rice (US$ 100 per hectare) is 5 times lower than the annual net return for vegetables (between US$ 500 and 1000). Thus a farmer will earn 5 times more with the cultivation of vegetables than that of rice. The change of the production towards higher yielding and more valuable market-orientated crops is possible due to the changing policy of the government. 169

In 1975 with the beginning of the communist regime, all the farmers worked collectively on government-run farms. After the reforms of the Doi Moi in 1986, the farmers had more freedom and earned the right to farm private plots of land and to let grow crops of their choice. However farmers still had to give a proportion of their production to cooperatives. From the mid-1990s the influence of the cooperatives decreased and the farmers could decide themselves where to sell their products. This freedom has lead to an increase of traffic congestion and pollution since the farmers transport their products individually towards the urban markets, resulting in thousands of extra vehicle journeys a day [Binns et al 2010: 3,5]. Due to the liberalization, the farmers living in the suburban areas altered their production from staple crops, such as rice, maize and sweet potatoes, to vegetables and subsequently to higher value products such as flowers and ornamental plants [Binns et al 2010: 4]. The new regulations of the government also encourage this process. The administration wants to make a modern city of Hanoi with only modern types of agriculture such as safe vegetables (not infected by pollution), flowers and ornamental plants [Binns et al 2010: 6]. The urban growth strengthens this process. When the government takes over farm land to turn it into new residential areas, she pays the farmers a compensation for their land. The compensation is based on the actual value that the land has for the farmer, resulting in higher compensation for vegetables crops than for rice paddies. Since the government doesnâ&#x20AC;&#x2122;t regulate the farming activities and changes in production are occurring, the use of fertilizers and pesticides have increased, causing soil, air and water pollution. Mostly the farmers donâ&#x20AC;&#x2122;t know which fertilizers are the best and how they have to use them. The changes have also created problems for the small rice producers. It may be hard for people to convert from rice to vegetables [Binns et al 2010: 7]. The floodplain of the YEN SO studied area contains a large agricultural site. The area is split by three administrative borders. The main part belongs to Hanoi Province. It consists of two suburban districts along the city centre: Thanh Tri district to the west of the river and Gia Lam district in the northeast. The area in the southwest and along the east dyke is part of Hung Yen province [van den Berg et al 2003: 43]. The largest decrease of agricultural land occurred in Thanh Tri district. The land is bought by the government to transform it into new residential areas. This process has increased the land prices and has forced the farmers to intensify their land use. Farmers who used to cultivate rice changed to the production of vegetables. In Gia Lam district the vegetables seem to have replaced maize [van den Berg et al 2003: 40, 41]. Thanh Tri district plays an important role for the vegetable supply of the city. The vegetable yields of Thanh Tri district are about 8700 kg per hectare more than the average for the whole province. This is due to the fact that the district is located downstream of the Red River and receives large amounts of nutrient-rich sediments. Over the years, the farmers of Thanh Tri district are having problems protecting their lower rice fields. They have to change from two rice harvests a year towards one harvest, giving up their rainy season crop due to the increase of flooding and the quality of the water. Most of them turn these fields into fishponds during rainy season [van den Berg, van Wijk, Van Hoi 2003: 43, 45]. 170

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The importance of the agricultural areas in the vicinity of the city is of great value for the liveability of the city as pointed out earlier. To ensure the conservation of the urban agriculture some considerations need to be taken into account. The value of the fields can still be upgraded. The uncertainty of their land to be taken over at some point in the future, discourage the farmers to make big investments to improve their production and to make it more sustainable. On the other hand, the government tolerance for modern and safer agricultural practices has motivated the farmers to develop production strategies in favour of more intensively grown, higher value crops. To move towards a more sustainable form of urban agriculture, the needs for the urban agriculture need to be incorporated into urban planning strategies and the plans have to be better communicated towards the farmers. Also a better working transport system needs to be developed to save time, money and resources and to diminish the individual traffic towards the city. The government has to implement a purification system to clean the water used for agriculture, to give the opportunity to produce safe vegetables in the vicinity of the city.

vegetable During the last years, the farmers have changed their staple crops into the cultivation of vegetables, since the vegetables are of higher value. Nowadays, most of the area in the floodplain are used for the cultivation of vegetables. 172

sand Next to the river, sand excavation are common use. The boats transport the sand towards construction sites in Hanoi and surroundings.

ornamental tree Some small areas are used for the cultivation of ornamental trees. They have a high value on the market what gives the farmers more yield.

vegetable sand

orchard On higher land, big orchards are located. The orchards in Du Duong in the northeast consists of guava trees. In general most of the orchards are banana plantations.

ornamental tree orchard

paddy field Paddy fields in the floodplain are situated in the lower areas next to the dykes. Previously 2 harvests per year were possible, but since more floods are occuring, the fields are too inundated during wet season for a second crop.

paddy field fish pond

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fish pond Since paddy field are inundated during wet season, the farmers turn them into fishponds. Some fishponds close to villages stay in service the whole year. 173

Red River Floodplain

3. networks The floodplain is characterized by a varied network of water bodies, canals, farming roads and ferries. First a closer look is given to the general structure of the water network and the different strategies for irrigation are mentioned. Secondly, an overview of the different road structures is given and the accessibility by different means of transport is tested.

1176 17 7water

irrigation canal

water network of the floodplain

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The Red River is the most striking feature of the floodplain. The WATER curves in the landscape creating impressive scenery. With its changing character it determines the use of the space around it. Most of the land is used for agriculture. A network of natural and man made irrigation canals spread the water over the land. Here and there some hydraulic machinery is put in place to control the water distribution. As seen in the sections from the previous chapter the topography causes the water from the river to flow inside the land, which creates lakes in the lowest land. Most of the lakes appear next to the dyke because the dyke stops the water from flowing to the lower areas across the dyke. This causes some problems to reuse the water during dry season. Since the lakes are on lower land than the fields, the water doesnâ&#x20AC;&#x2122;t flow naturally across the fields

towards the river. A controlled irrigation system has to be developed to ensure the production during the whole year. Near the villages some lakes are used as fish ponds. The water stays there permanently. Other lakes only exist during rainy season. In dry season they are used for agricultural activities. The flushing makes these fields very fertile. In the north-west buildings have taken the place of the water. Everything is transformed into roads, houses and factory grounds. The city is increasing inside the floodplain and is destroying the ecological system. The farming activities seem to get lost. The changing character of the Red River is neglected, which brings problems during rainy season when the water level of the Red River is remarkably increasing and the chance for floods is high.

177

178

Irrigation canals

Pumping mechanism

Concrete canals are put in place along the agricultural fields to be able to control the water stream for the agricultural activities.

Little pumping stations provide the fields on higher ground with water during dry season.

Yen So pumping station Pumping mechanism

Irrigation canals

water

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Yen So pumping station This engineering mechanism pumps the waste water from the city over the dyke. The water flows without purification via a canal in the Red River.

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high way dyke

main road sub road

farming road ferry route

road network of the floodplain

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The

floodplain is impregnated with Mostly they are small earthen roads, only accessible by bike or motorbike. The paved roads are located perpendicularly between the dyke and the river. They connect the villages in the floodplain with the dyke. The small agricultural roads along the fields follow the rectangular grid of the fields. The roads passing through the villages have a more irregular pattern.

with the vegetables they have harvested and bring them to the villages or drive directly to a local market.

In general a car can drive into the floodplain via several roads but there is no connection between the roads. The car has to go back over the same road it came from. This is why only cars and small trucks which are transporting the goods of the industry next to the river, the potteries from Bat Trang and the harvest of the fields drive in this area.

Three FERRIES and the Thanh Tri Bridge provide the connection between the two sides of the river. The bridge connects the two inside dyke areas. It spans the whole floodplain. The three ferries are used by the farmers who are working in the fields in the floodplain or in the inside dyke area to the east. The ferries play an important role for the accessibility of the area. For the moment transport over water occurs generally from one side to the immediate opposite side of the river. Only boats with sand navigate up and down the river.

ROADS.

Since the road network is not made for cars, bikes are commonly used. The farmers load on their bike the baskets

As seen in the sections of the Floodplain Sections chapter, the roads are higher than the fields. However, only the concrete roads and the subdyke reach the level of 8,5 metres above sea level which makes them accessible during flooding in rainy season.

181

Ferry

Car road

The ferry brings local people straight from one side to the other side of the Red River. Farmers on bikes with baskets full of harvest use the ferry to go to the city to sell their goods.

During wet season the roads used by the trucks between the dyke and the industry close to the river are turned into a quagmire most of the time.

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ir ir

high way dyke

main road sub road

farming road ferry route

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Farming road

The sub dyke is a concrete road, located 8 metres above sea level. People on motorbikes or bikes use it to go in the direction parallel with the river. Apart from the areas around the industry and the village Bat Trang it is not possible to drive on it by car.

The farming roads cross the floodplain along the fields. These roads are approximately 1 metre higher than the surrounding agriculture.

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Red River Floodplain

4. planning for the future This section focuses on the current master plans concerning the Red River and its dyke system. As these master plans are discussed broadly in the Water Urbanism Thesis of 2008-2009, this section will only highlight the strategies that concern the floodplain, the illegal settlements located outside dyke and the dyke system itself. By mapping the master plan of Vietnam, Japan and Korea on the same scale, and by using typical concept sections of the floodplain, this section briefly compares the 3 master plans, and evaluates them critically on the highlighted strategies in a short conclusion.

All maps of this section are mady by Tuan Pham Anh and elaborated by the authors.

CURRENT SITUATION Nowadays, the floodplain spans approximately 7 km at its widest point, bordered by dykes that can stand a flood of 14.13 meters. As seen in ‘Yen So water history’ the river is still shifting over time in between this rigid dyke system. Subdykes maintained by villagers to protect both village and agriculture are to be found closer to the river, but do not form a strict dyke system as they differ in height and their continuity isn’t always guaranteed.

note on the water levels in the sections:

floodplain road network

+14m +11,6m

existing dyke bridges existing subdyke 8-10m

3km

existing dyke +14m

+14.0m water level at 125-year return period +11.6m water level at 5-year return period +7.0m average water level may - oct +4.0m average water level nov-april [Haidep study team]

illegal settlements

existing urban area

outside dyke area

inside dyke area

+7m +4m

186

Typical concept section current situation

floodplain water levels

existing dyke

VIETNAMESE MASTERPLAN The Northern Hydraulic Planning Institute designed a master plan for the upgrading of the dyke system. These plans are currently elaborated. The aim of the master plan is to widen the current dykes to 15 metres on the right bank and to 12 metres on the left bank. On top of both dykes a wall of 1,5 metres in height and 1 meter in width will be constructed. Moreover stone embankments will be erected in places that are most prone to flooding. Besides looking at the dyke system itself, the Vietnamese master plan also focuses on the points of connection â&#x20AC;&#x201C;like sluices and pumps- in the water network. In 2005 phase 1 of the biggest pumping station was realised, phase 2 of the Yen So Pumping Station is still under construction. [Pham Anh 2009 b]

existing dyke new dyke

area for urban development

+14m +12,03m floodplain class 1

+11,6m

3km

existing urban area

+10,89m floodplain class 2

+7m +4m

cutting land

main usable land

outside dyke area floodplain area of cut and fill

new roads bridges

existing dyke +14m

stone embankments

floodplain road network

existing dyke new dyke

water levels

Typical concept section Vietnamese Masterplan

inside dyke area 187

JAPANESE MASTERPLAN a second dyke for Hanoi

+11,6m

existing dyke new dyke

bridges

3km

existing dyke +14m

floodplain road network

new dyke + 12m

+14m

river embankment

The Comprehensive Urban Development Programme in Hanoi Capital City of the Socialist Republic of Vietnam (HAIDEP), a cooperation between Hanoi Peopleâ&#x20AC;&#x2122;s Committee and Japan International Cooperation Agency (JICA), has investigated an area of 40 km along the Red River that is taking into account the current dykes, the river, and the illegally appropriated river banks [Pham Anh, Shannon 2009 b]. Until recently the urban expansion of Hanoi was planned to go northwards across the Red River. As the possible urban pressure on the environment put a hold on this plan, the current expansion is now planned westwards. In this vision, HAIDEP recognises that the area outside dyke has an important historical value, and that its disaster prevention capacity is a key element for the city [HAIDEP study team 2007:69]. For the sake of the implementation of the flood control strategy, the plan proposes a second dyke system closer to the river. Besides enhancing the development potential of the outside dyke area, and securing the peoples quality of life, one of the argumentations for the second dyke is the protection of areas with high cultural values, such as the outside dyke villages of Bat Trang and Phuc Xa. This dyke system is designed at the height of flooding for the 5-year return period, this way allowing limited development projects in the area between new and existing dyke [Pham Anh, Shannon 2009 b]. A supporting policy is made: a no development zone for the areas lower than the average high water level (+ 7m) is foreseen flanking the river with green space, while the zones between +7m and 11.6m are determined to be open space zones. Controlled development in ways of a non residential zone is foreseen in the area between the new dyke and the existing dyke [HAIDEP study team: pilot projects 2007:C-3-5].

area for controlled development

existing urban area

+7m +4m

outside dyke area 188

Typical concept section Japanese Masterplan

inside dyke area floodplain water levels

existing dyke new dyke

KOREAN MASTERPLAN superinfrastructure

existing dyke new dyke

new roads bridges

3km

existing dyke +14m

floodplain road network

new dyke + 14m

“From 2006 to 2007, a cooperation research between the capital cities of Hanoi and Seoul worked to develop lessons learned for the Red River from the Han River. The project sought to marry flood control with new urbanization, economic drive, river-based recreation and identity. The development of an infrastructural system and dyke system became the backbone of the entire project, upon which was grafted an entire new high-rise city, new landscape system and waterfront area along the entire length of Hanoi’s Red River” [Pham Anh, Shannon 2009 b: 16]. The urban development and improvement plan around the Red River was established in connection with the existing ‘Hanoi City 2020 Master Plan’ and consists of 3 sub-plans: a riverside park creation plan, a riverside road construction plan and a Red River Improvement plan to link abandoned river sides with comprehensive urban planning. Focussing on flood control, the Red River Improvement plan implements current dyke reinforcement, slope protection to stabilise both riverside and dykes and the improvement of the river channel to increase the capacity of flood flow [The Red River Project Team 2007]. The plan also proposes the building of a second dyke. As compensation the banks of the river will be excavated in some aeras [Pham Anh, Shannon 2009 b]. In this new alignment plan, the current dykes will continue to exist because of their historical and cultural value. Moreover they will act as a second protection for flooding. Following the Riverside Road Construction Plan, the dykes become the main arterial roads to Hanoi, flanked with a car-based super infrastructure. Pedestrian access from city to river is therefore made via a series of landscape bridges crossing the arterial roads [Red River Project Team 2007: 7-52 to 7-53]. Furthermore, a migration plan is needed to comprehensively review the relocation of the residents in the river side area and to establish migration and living plans for residents who lost their farmland due to the change of the dyke alignment [The Red River Project Team 2007: 3-9].

+14m

area for controlled development

+11,6m

existing urban area

+7m +4m

outside dyke area floodplain water levels

existing dyke new dyke

Typical concept section Korean Masterplan

inside dyke area 189

CONCLUSION All of the discussed master plans are reducing the floodplain area by proposing a second dyke system closer to the river. In a slogan that attempts to harmonise water, nature and culture, all 3 master plans neglect the fact that nature in general and water in particular need space. In this logic, the Vietnamese master plan is the most radical as it aims at canalising the Red River â&#x20AC;&#x201C;a project that has been proposed and rejected 90 years earlier. Though, the Vietnamese master plan is the only master plan that puts the plugs of the water network, being the pumps and sluices, highly rated on its agenda. Not only is the floodplain reduced in area, the second dyke line proposed in the 3 master plans is levelling higher than the current ones, leading to more catastrophic situations in case of dyke failure.

Furthermore a second line of higher dykes also forms a second barrier for the water from inside the city going towards the river, resulting in a second system of pumping station and sluices needed for the concept of a dyke to work, as the city is lying lower than the floodplain and natural water drainage is impossible. One can ask if the development cost will pay itself back this way, as the resulting positive yield is the first point of attention of all 3 master plans. As the Red River is known for its sediment, the building of a second dyke system closer to the river will soon lead to the building of a 3th dyke system as the floodplain is heightened up naturally flood after flood, resulting in a higher water level each time. Next to these water related issues, the proposed infrastructure of the Korean and Vietnamese master plans are critical as well. As the Korean master plan introduces the

Ca Lo River

dyke as an arterial road system for Hanoi, the question rises whether the dyke in this context will not generate urban life at both sides, while the Korean master plan envisions high rise buildings in the outside dyke area. The Vietnamese master plan is widening the current dykes as well, resulting in the same kind of situation: urbanisation along axes of connectivity. Furthermore, the Korean master plan also proposes the building of the RR4 Bridge, a bridge that was foreseen in the 2020 master plan for Hanoi sprawling across the river to the northeast. Crossing the floodplain at its widest point will automatically generate an exuberant urban pressure on the natural environment, leading to a situation in which all cultural heritage located inside the floodplain will get lost, and in which the floodplain as a biotope for agriculture and water is no longer possible.

HANOI Van Giang Thanh Tri

Cau River

Day River

Red & Da River 190

Canalisation of the Red River In the 1920s, the Nguyen Court engineer (Nguyen Canh) proposed a radical engineering project to canalize the Red River in order to improve the water discharge in the rainy season and to let water flow as fast as possible to the East Sea [Pham Anh, Shannon 2009b: 7].

Ba Lat Estuary Lien Giang River Duong Canal

Thai Minh Canal

Ninh Ca River Phu Ly Canal Nam Dinh Canal 0

2,5

7,5km

Red River existing dyke

urgently built dyke limited river bed

limited river bed

Hoanh Nha River 191

Dyke

connector

A. Methodology

This chapter focuses on the dyke itself. By crossing the scale of Hanoi and Yen So, different themes are mapped. Firstly the dyke on the scale of Hanoi is taken into account. Water structures that flank the dyke on both sides are compared, and the changing atmospheres as well as most occurring local events along the dyke are mapped and visualised. Secondly a zoom in on the scale of Yen So deals with more local structures such as the connection of villages to the dyke. Lastly, the chapter ends with a more focussed look on the dyke and its spatial appearance while driving along it.

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dyke, scale Hanoi

3km

dyke, scale Yen So

200m

Hanoi

Yen So

3km

Red River and dyke, scales

195

B. Water barrier The EAST DYKE separates 2 water systems: the curved line structure of the Red River outside the dyke area, and the multiple lakes inside the dyke area. As seen in the sections H till O, the Red River bank slants down from river to dyke, creating lakes in the lowest area. These lakes form productive paddy fields lying next to the dyke. Below Bat Trang, the Bac Hung Hai river crosses the massive dyke through a sluice, continuing its flow through the fields up to the Thai Binh River, 40 km east of Hanoi. This river is flanked with a subdyke system as well.

196

water dyke 14m

village

subdyke 4-8m highway

railway main road

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east dyke: water separator

Yen So

Bac Hung Hai River

Yen So 0

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WEST DYKE, like the east dyke, separates 2 similar water systems: the Red River and the lakes inside the dyke linked by the channels. The difference is that in this case the dyke works as a water barrier instead of a separator since the dyke prevents the city from being flooded, but it also obstructs the water that can not be absorbed by the soil in the city going to the river. On top of natural topography, this is one of the reasons why Hanoi has to deal with city floods as was the case in 2008.

The

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water dyke 14m

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Yen So

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west dyke: water barrier

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As the DYKE is an element that works in two ways, meaning it both protects and causes the city to flood in case of heavy rainfall in urbanised areas, the question rises if heightening the dyke in the future to protect the city against floods is the right intervention. Since heightening the dykes would also mean having a more advanced system of pumps to set free the city from its water problems. One of the challenges of the future dyke could be to act as a water MEDIATOR by taking the current water problematic into account and intertwining the water structure of the river on one hand and the water structure of the lakes and channels on the other hand in an engineered way. The Yen So Pumping Station can therefore be seen as a first step into this way of thinking.

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dyke 14m 1,2 location of pictures

1 To Lich channel

2 Yen So pumping station

Red River, view on east bank

201

C Changing atmosphere The curve of the EAST DYKE seamlessly threads through different atmospheres going from north to south. Starting at the crowded city-like character at the Long Bien Bridge and passing specialised craft villages all the way to the more deserted agricultural based region, it is most noteworthy that the dyke itself remains of similar form and that the road is a continuous line of 6m width.

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dyke 14m

bridges location of pictures

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west dyke: changing atmosphere

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The WEST DYKE knows a more extreme evolution. In the north, at the Long Bien Bridge, the dyke is an impressive road infrastructure, containing 4 traffic lanes one way and an equal 4 the other way. The atmosphere is one of booming city life, with all kinds of people and vehicles on the move, flanked by rising hotels: itâ&#x20AC;&#x2122;s an incredible jungle of traffic lights, motorbikes (motor horns inclusive), heavy loaded saleswomen, cars and pedestrians. All this movement takes place in front of a fresh scene: the dyke wall decorated with kilometres of colourful mosaics, sponsored by investors, and made of Bat Trang ceramics for the 1000 year Hanoi festivities [www.hanoimural.vn]. In sharp contrast to this city life, the most southern point of Yen So is characterized by an earthen dyke where only local traffic and a bus pass over a road that is about 6m width.

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dyke 14m

bridges location of pictures

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west dyke: changing atmosphere

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There is a big difference in character when looking at the EAST and WEST DYKE though both are mapped as equals on traffic road maps. The core of this difference lies in the fact that these 2 sides both link other atmospheres: while the east dyke only links city with agriculture, the west dyke has to tie city, periphery and agriculture together. While the dyke and the dyke road at the east side are an element of continuity, at the west side the dyke and its complementary dyke road changes in form while crossing its 3 atmospheres.This means the dyke itself shows sudden discontinuities, as there is the end of the mosaic mural at the Long Bien pier, and other sudden changes like the hierarchy in car lanes (the dyke evolves from a 4 by 4 car lane from west lake to Long Bien Bridge, to a 2 by 2 car lane from Long Bien bridge to the beginning of the yen so area where it ends up in a 1 by 1 car lane). This way it

206

West dyke near Long Bien bridge

is also clearly understandable that the dyke on the east side only carries local transport like motorbikes with harvest, cars with tourists for Bat Trang, small trucks with goods from the craft villages or the bus that drives once every hour to the city centre. On the contrary, the dyke on the west side is vulnerable as a result of the city willing to grow, and the heavy loaded trucks with sand that come with it. Due to this pressure, the west dyke from the most southern bridge to the Yen So pumping station is slowly changing into a dust tunnel with holes in the road due to the overloaded use of the dyke.

West dyke near Yen So pumping station

207

D. Local events

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dyke 14m local events

bridges

dyke road reconstruction badminton field bar on dyke wall

Long Bien bridge

park with sugar cane bars

dyke wall construction

Though the traffic is largely local, lots of activities take place along the EAST DYKE, most of them related to dyke improvements as a preparation for the 1000 year Hanoi festivities in Bat Trang ceramic village. The east dyke is characterised by a busy atmosphere: each crossing is topped with a local market and sugar cane bars along the road are very popular. Even garages and a taxi rank are located near the biggest crossing. All these activities are small scale in comparison with the dimensions of the dyke. The exceptions to this are the Hanoi handicraft village and the Ecopark that are both enclosed by the dyke.

0 250 1000m

east dyke: local events 209

bar

grazing buffalos

pagoda under constructiion

grazing buffalos

ceramic flower pots drying

bars and taxi rank

Yen So

pagoda

local market garage

fish pond

dyke reinforcement

brick storage

sugar cane bar

strictly guarded ecopark

hanoi hand craft village

Yen So

lime saleswomen

bar and Xe Ohm

pagoda restauration

dyke reinforcemnt

dyke wall construction

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dyke 14m local events

bridges

karaoke street

bars and bus stand

long bien market long bien bridge

flower market

honda & lexus showroom

oke street as well as the car showrooms are the only events directly related to the dyke on a bigger scale. Furthermore, in between the 2 middle bridges several outside dyke villages are connected to the inside dyke city by only one opening in the dyke wall. These villages form big entities along the figure of the dyke. In this area few bars are found along the road. More south, the Yen So Pumping Station forms a huge infrastructure connected to the dyke linking city and floodplain. Following the road up to the south results in very local scale events like few saleswomen on a crossing and some grazing buffalos.

en nclosed village Duong Bach enclosed

Less events take place along the WEST DYKE. The flower market and the kara-

0 250 1000m

west dyke: local events 211

end of wall

saleswomen horse

dyke under construction

bars

grazing buffalo

Yen So pumping station

row contest

filling station

Yen So

Both dykes only know very SMALL SCALE EVENTS compared to the big

dyke infrastructure. Most of these small scale events are culture related like bars, or linked with the profession of ceramics, ornamental tree growing or agriculture. Because the east dyke is linking floodplain and similar agricultural based area inside dyke, its crossings are places of meaningful social life, the east dyke therefore being a carrier of lots of local events. The west dyke on the contrary is used as an arterial road from city to periphery, which makes small scale events and bigger activities uncomfortable near this high speed traffic.

bar on east dyke, Bat Trang

212

bar on west dyke, Duong Bach

salesman on east dyke, 1km north of Bat Trang

saleswomen on west dyke, Long Bien Bridge

213

E. Village connector A wide network of motorbike slopes and more drivable concrete roads connected to the EAST DYKE form a MAZE that gives access to several villages in and outside dyke. As can be seen on the map this big road network increases the connectivity but it also increases the danger of driving on the dyke since all of these motorbike slopes are created without following rules and therefore formed where needed. This way driving on the dyke means being prepared at any time for a motorbike driving on a parallel road suddenly coming up on one of these small slopes and crossing your way unexpectedly.

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dyke verge and road

village industry

concrete car road earthen motorbike road and slope

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500m

Yen So: the east dyke as a village connector

215

A similar system works on the WEST DYKE as well, only this time the for-

mation of roads forms a more organised and EFFICIENT NETWORK in stead of a maze. Noteworthy are the numerous concrete roads perpendicular to the dyke that form big crossings, linking industry and villages near the Red River directly with the dykes main road.

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dyke verge and road

village industry

concrete car road earthen motorbike road and slope

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500m

Yen So: the west dyke as a village connector

217

Like for the east dyke, on the west dyke the MEANDERING DYKE ROAD is the main arterial of the maze/network, linking villages with agriculture, villages with dyke, dyke with industry and villages with each other. While the road connected to the east dyke form a maze with a dominant amount of informal motorbike roads, the west dyke knows a perpendicular and efficient network system. On both sides, the villages lying in the floodplain are merely connected with the dyke than with each other, making these roads the shortest way to the highest point in case of a rising river.

218

200

600m

dyke verge and road

village industry

concrete car road earthen motorbike road and slope

informal motorbike road to east dyke

concrete road linking east dyke with village

219

Yen So

F. Sequence of openings

220

221

Yen My

Starting at the West Lake and ending on the most western point of the dyke in Yen So located near Yen My, the west dyke is heightened up with a CONCRETE WALL as a response to the flood of 1971, making the dyke hereby possible to protect the city from floods up to 13.30m above sea level [Interview with Tran Van Dien by Pham Anh 2009:10]. Crossing kilometres of dyke and linking different atmospheres from centre to periphery, this massive wall remains a strict element of continuity. In the centre decorated with mosaics, the wall gets its rough imago starting in Yen So, where its appearance is defined by small differences every kilometre: light, use of dyke road, the composition of the concrete and the colour of the joints are only few param-

222

eters. Driving along the wall, an awareness of a SEQUENCE OF OPENINGS appears unnoticed. All of these openings are connections to villages or industry lying in the floodplain, and therefore lying outside dyke. These openings being the weak points of the dyke, each is foreseen with concrete beams which need to be put into place to close the dyke in case of flood. A game of access and entrance, hiding and appearing takes place along the dyke, with each opening giving way to a Hanoi that is completely different than the well known city centre.

sequence of openings: Nhà Tho’ xã Trãn Phú Church

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dyke verge and road road

village industry

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50 50

150 150

250m 250M

sequence of openings: Phuong Thanh Tsi

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dyke verge and road road

village industry

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250m 250M

sequence of openings: Thuy Linh road

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228

dyke verge and road road

village industry

road

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150 150

250m 250M

sequence of openings: local traffic road to Red River ferry

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dyke verge and road road

village industry

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sequence of openings: concrete industry

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dyke verge and road road

village industry

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sequence of openings: Yen So Pumping Station

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dyke verge and road road

village industry

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sequence of openings: Yen My

235

conclusion and design strategy

Red River Delta as a sponge Efficient use of tributaries, branches, lakes and irrigation canals to soak up the excessive water 238

Combining Strategies Questioning the hybrid dyke Titled “hybrid dykes in Yen So”, this thesis’s aim was to integrate the current logics of water management, infrastructure, urbanisation and landscape by re-thinking the concept of the dyke, and putting forward the hypothesis that a hybrid dyke could be the key to this aim. Through the process of analysing and designing –a research by design- the current water management and the massive city pressure turned out to be the two dominant players of the game, rendering the hybrid dyke only a small part of the solution.

Water edge Hanoi is raised by its dykes. Forming a well working pivot between water and city, the dyke has always been the edge for the river. This story has been true for almost 1000 years, but by drawing the hard line between river and city, the possible outcomes of climate change and the process of sedimentation that heightens up the riverbed flood after flood were not foreseen. The first results in a situation in which the current dykes aren’t high enough to resist sudden increase of river water caused by heavy rainfall. For this case raising and hardening the dykes could be a solution, but not a sustainable one. The latter results in a process that is levelling the river higher than the city each time the rivers sediment redraws the topography outside dyke. On the long term this natural process could be a smaller contributing factor to the strategy in which dykes need to be raised in order to keep the water out of the city. Furthermore, the water problematic of the Red River Delta isn’t only facing challenges concerning climate change: dams and hydraulic power plants are being built in both Vietnam and China and as the communication with the latter isn’t transparent, sudden excessive water can be expected at any time. Therefore, a resistant hard engineered dyke system that can be redesigned on the scale of Hanoi should not be the only solution to rely on. Reviewing the current water management of the entire Red River Delta could provide a more sustainable and broader solution in which the delta as a whole should act as a sponge, using his network of tributaries and branches to soak up the sudden excessive amount of water, and draining off the alluvial sediment. 239

Inner city water network An increase of the soaking capacity is created by linking canals and rivers with lakes that can function as retention areas. This way drainage, storage and pumping are combined. 240

Facing river floods, Hanoi is plagued by city floods as well. In 2008 the river crossed the dykes, topped with persisting heavy rainfall this resulted in the inundation of the city. Streets became rivers in a city that sealed its soil by a massive and sudden urbanisation, filling in its lakes for building purpose. The city having little permeability left, and the engineered water network not being adapted to the sudden urbanisation, the water was trapped in the inside dyke area, the dyke being once more an edge for the water. As the city is bordered by dykes and the process of sedimentation has heightened up the riverbed, natural runoff is impossible. Therefore, the water management has always been based on the idea of collecting water and pumping it out of the city through a series of smaller pumps. Yen So, being the lowest area and therefore the water collector of Hanoi plays a key role in this water management logic. A first step into an improved water network on a larger scale was made with the realisation of the Yen So Pumping Station in 2005 that uses the lowest area of Yen So for water storage. However this system seemed not to be enough, resulting in a second pump in order to increase flow rate by 2010. This way, the Yen So Pumping Station, grafted on the dyke, became the first large scale infrastructure to merge city and river in ways that it plays a key role in the current water management. Nowadays the To Lich River, the Nhue River, the Lu River and the Set River are linked artificially in order to gather and collect the water in the Yen So Lakes, used as retention pond in the periphery of the city. Acknowledging the concept of the sponge on the larger scale, the same concept should be introduced for Hanoi and its inner-city rivers that are responsible for draining the city. In stead of cutting off rivers and relying on 1 pumping station to keep streets from being rivers, the soaking capacity of the natural network should be used in combination with the engineered pumping station. This way Hanoi can increase its absorbing capacity by means of using its big amount of lakes, rivers and channels to combine strategic collection of water and natural drainage inside dyke with pumping outside dyke. 241

The floodplain as a void in the urban tissue On a larger scale the floodplain and lakes of Hanoi form voids in the sprawling city. 242

Sprawl edge Seeing as the massive urbanisation Hanoi has gone through the last decades, the city is becoming denser, making any form of open space endangered. Paddy fields and lakes are being filled in and agricultural plots are quickly replaced by new high rise buildings. Mapping the city on a larger scale, the floodplain occurs as a big void in the urban tissue, flanked by white dots being lakes. Acknowledging the above named water issues, it seems that the role of the dyke has been turned inside out and that the dyke seems to protect the river bed from being urbanised more than it is protecting the city from being flooded. But by zooming in on the riverbanks of Hanoi it seems that a dyke breach has occurred, causing the city to flow into the river as a result of the urban pressure. The dyke carries in its concept that it borders the ‘free zone’ for the river, but as seen in the section ‘urban tissues’ it is obvious that the dyke as a protector for the free zone is not working in the Vietnamese context and that it therefore fails to act as an edge for urban sprawl. Policies order no build zones along the dyke and in the floodplain, but as natural topography, connectivity and land cost are favourable in these places, Hanoians lack the rules and claim land.

Combining strategies Through the process of researching by design the main answers to the current water issues were not to be found on the scale of the dyke itself. In a context that has survived for almost 1000 years with the concept of resistance in ways of building dykes and hardening edges to protect itself, the big gesture for Hanoi is not to propose an alternative dyke system that ties together the current principles of resilience by softening the hard edges. The big gesture is to take into account the current resistant strategy of the dykes and to combine them with a more resilient strategy that sets free and makes smart use of the zones the water has nowadays. In the rigid network of the dykes along the Red River there 243

250

1000M

0 100

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1000m

Current situation of the Yen So floodplain As Yen So is the place where the floodplain is at its widest, the river still has space to shift in time. The goal of the design projects is to prevent the floodplain from further urbanisation, as city pressure is pushing settlements outside dyke. 244

are still spaces to be found for the water that are not in optimal use nowadays. Therefore, next to the concept of the sponge for the Red River Delta and the inner-city rivers, the outcome of the thesis is to protect the little space the river has left in between the dykes. Though we are not able to give more room to the river in a strict sense, we are able to prevent room from the river to be taken away.

Design In this strategy the design projects focus on the floodplain of Yen So, as it is the place where the river is at its widest between the dykes and were the landscape of meanders is still an ongoing process. It is the place where the floodplain gathers a rich amount of villages with a traditional culture in crafts and agriculture. As Yen So is the lowest point, this is the area where the water issues come together and where the Yen So Pumping Station is grafted on the dyke. Moreover, located in the periphery of Hanoi, the floodplain of Yen So is not yet fully urbanised, but as the city keeps on growing, settlements are sprawling in the floodplain in the north already. This factor combined with the fact that the floodplain is at its widest and that this area is seen as possible building space in case of a canalised river as proposed by lots of master plans, a strategic project that puts the floodplain in the mental map of the Vietnamese can be seen as establishing a precedent. Therefore the design will focus on the questions of how to prevent room being taken away from the river, how to set free the floodplain from further urbanisation and how to make it a common tread amongst the inhabitants of Hanoi. The goal is to make Hanoians aware of the river their city is founded next to in stead of the lacking attitude that nowadays rules in ways which it is feeling safe inside dyke while neglecting what is outside dyke until it crosses front doors.

245

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Interviews Chien, Yen My, 24/08/2010 Mr Nguyen, Phuong Liet, 06/09/2010 Hang, Phuong Thanh Tri, 23/09/2010 Nhung and Hung, Tang Cao, 5/09/2010

All images in this booklet are, unless listed below, made or drawn by the authors.

Section Flow of the river Map delta: based on map from database Mahs/Mausp Studio KULeuven, Spring 2009. Map reservoirs: based on map in: BABEL, M.S., DANG, N.M., LUONG, H.T., “Evaluation of the flood risk parameters in the Day River Flood Diversion Area, Red River Delta, Vietnam”, in: Natural Hazards, 2011 (56) , nr. 1, p.173. Map Day River: zoom of map delta. Picture Day Dam: Picture in [Kok 2006: 7].

Section Landscape of Meanders Maps Holocene, 1911, 1935, 1935, 1996, 2000, 2010: based on historical maps received from Tuan Pham Anh, doctorate student at OSA KULeuven and Mahs/Mausp Studio KULeuven, spring 2009.

Section Urban Sprawl Map 1885, 1935, 1972, and 2000: based on historical maps received from Tuan Pham Anh, doctorate student at OSA KULeuven and Mahs/Mausp Studio KULeuven, spring 2011. Map 2010: based on Google earth 2010, last checked 15/05/2011. Data time line: data from Pham Anh, doctorate student at OSA KULeuven. Dyke profiles: based on sketch of Pham Anh, doctorate student at OSA KULeuven. Drawing dyke profile: GAUTHIER, J., Travaux de défense contre les inondation – Digues du Tonkin, Imprimerie d’extrême-orient, 1930. p.97.

Section City Floods Picture drought: picture from database Mahs/Mausp Studio KULeuven, spring 2009. Picture wet: picture from database Mahs/Mausp Studio KULeuven, spring 2009. Map estimated total rainfall: produced by United Nations Institute for Training and Research (UNITAR) Operational Satellite Applications Programme (UNOSAT). Picture fruit seller: taken by GETTYIMAGE, http://www.independent.co.uk/news/world/asia/thousands-evacuate-as-vietnam-capital-battles-flood-993649.html. Picture motor bikers: taken by GETTYIMAGE, http://www.independent.co.uk/news/world/asia/thousands-evacuate-as-vietnam-capital-battles-flood993649.html. 250

Section Yen So water history: Map 1911, map 1935, map 1972, map 1996, map 2000: adapted from Tuan Pham Anh, doctorate student at OSA KULeuven.

Section Tissues - Methodology Map Yen So 2010: based on mapping of Yen So area made by Tuan Pham Anh, doctorate student at OSA KULeuven. Tissues: based on Google earth 2010, last checked 31/10/2010. Map evolution Yen So: based on mapping of Yen So area made by Tuan Pham Anh, doctorate student at OSA KULeuven.

Section Tissues - Urban growth Masterplan 2020: based on Tuan Pham Anh, doctorate student at OSA KULeuven. Sketch situation of Phuong Liet in 1945: based on drawing of Nguyen Chac Thinh from the Communal House of Phuong Liet. Picture women playing badminton: taken by Erik Vandenpoel, 28/09/2010. Map topography: based on topographical map, obtained from GIS information, received from Tuan Pham Anh, doctorate student at OSA KULeuven. Picture dyke flood 1926: picture from Aéronautique Militaire in: GAUTHIER, J., Travaux de défense contre les inondation – Digues du Tonkin, Imprimerie d’extrême-orient, 1930, p.21. Picture Bat Trang flood 1926: picture from Aéronautique Militaire in: GAUTHIER, J., Travaux de défense contre les inondation – Digues du Tonkin, Imprimerie d’extrême-orient, 1930, p.35.

Section Agriculture Map districts: based on [Van Den Berg et al 2003: 45]. Picture agriculture floodplain: adapted from Google earth 2010, last checked 26/03/2011. Picture agriculture patterns: adapted from Google earth 2010, last checked 26/03/2011.

Section Networks Water floodplain: based on Google earth 2010, last checked 26/03/2011, mapping of Yen So area made by Tuan Pham Anh, doctorate student at OSA KULeuven and own fieldwork. Roads floodplain: based on Google earth 2010, last checked 26/03/2011, mapping of Yen So area made by Tuan Pham Anh, doctorate student at OSA KULeuven and own fieldwork.

Section Planning for the future: Map current situation, map Vietnamese master plan, map Japanese master plan, map Korean master plan, map canalising red river: adapted from Tuan Pham Anh, doctorate student at OSA KULeuven.. Section Vietnamese master plan, section Japanese masterplan: adapted from Tuan Pham Anh and based on Haidep Study Team, Main Report p 480.

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