The Human Habitat
Reconnecting Ecological Concords of Peri-urban areas of Ahmedabad
Navyatha Thabjula PG180580 1
Studio Brief LA4004: Designed Ecologies Tutor: Deepa Maheshwari, TA- Kauseen Motiwala Course Introduction The course looks at designing new ecologies for constantly developing cities that address highly stressed and conflict areas which can be manipulated to bring new meanings in the present scenario. For a long period of time, we have existed with a sense of dualism between nature and the city. This phenomenon has led to crossroads upon which there are conflicts that begin to occur within our existential realm. These conflicts encompass a wide variety of attributes ranging from ecological disruption to social constructs being affected. Conflict areas often are highly stressed pockets that require an in depth and empathetic approach that may begin to read the hidden text. It is the need of the hour to propose paradigms of designed ecology to rebuild, support and recollect gradually fragmenting land mosaics. These devised ecosystems take time to evolve and are often the outcome of multiple interactions that are dynamic in nature, operating over multiple scales across socio-economic and biophysical processes. The resilience of a city - the degree to which change is acceptable before reorganization to create a new set of structures - is highly dependent on these interactions.
Problem Statement It is common to see that urban green areas today are economic and environmental burdens due to high maintenance, largely because they are artificial and energy intensive. They are conflict areas that were once part of natural processes and now burdened by developments. Thus they present challenges and opportunities to deal with environmental issues and improve their conditions.
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Abstract
The journey of the project starts by comprehending the need of the hour in cities, the physical and mental problems caused by improper development of cities with respect to the change in natural elements in the urban fabric. It is of due importance, as negligence in socio-cultural practices and dynamic growth patterns of the city have led to the city and its environment to a much degraded state. Studying these, we were able to access the most highly affected or stressed areas or conflict zones which have either been altered, modified or are in an endangered state. These conflict zones occur due to a number of factors which have been labeled on the map. Selecting of the conflict zones- this site specific zone was endangered due to multiple development issues which led to the degradation and encroachment of the natural elements on the site. A more in-depth analysis based on the layers such as changes in development patterns and alterations in habitual methods of living altered the natural layers in its form and function. Through the use of previously studied methods of landscape interventions for such scenarios, a development based on certain environmental friendly methods were targeted to be implemented in the study area for the improvement and adjustment of the natural elements. A set of guidelines were explored and established to incorporate the ecological diversity of the region and to demonstrate how such designed ecologies can be weaved into the existing fabric so that it enhances a number of factors like canopy cover, biodiversity, etc. for the well-being of the city, humans and environment. The solutions further if implemented for zone specific problems through the whole region in the city, it could immensely increase the quality of livelihood and quantity of natural cover within the city as deemed required by W.H.O guidelines.
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Contents
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Studio Brief
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4.
Site Analysis
Abstract
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1. Introduction
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1.1 Natural Systems 1.2 Benefits of Ecosystems 1.3 Impact of Cities on Natural Systems 1.4 Ecological Conflicts 1.5 Fragmentation- Site 1.6 Vision Statement 1.6.1 Aim 1.6.2 Objective 1.6.3 Methodology
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4.1 4.2 4.3 4.4 4.5 4.6 4.7
Chronology and Potential of Site Ecological Habitats on Site Existing Fauna Issues on Site Elevation, Ridges and Watershed Existing TP Scheme Proposal-2021 Ecological Impacts After 2000
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Case Studies
2. Ahmedabad
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2.1 2.2 2.3 2.4
Defining Greens of Ahmedabad Statistics of Green of Ahmedabad Chronology of Ahmedabad Fringes 2.4.1 Extent of Fringe 2.4.2 Extent of Change 2.4.3 Scale of Growth 2.4.4 Conflict Areas of Ahmedabad
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Site Introduction
3.1. 3.2. 3.3.
Larger Context Site Justification Larger Context- Sabarmati River
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5.1. Case Study 1 - Nantong Eco-Corridor 5.2. Case Study 2 - Sanlihe River Ecologicalcorridor 5.3. Case Study 3 – Metro Forest Project 5.4 Case Study 4 - Adyar Eco Park, Chennai 6.
Design Development
6.1 Systems Diagram 6.2 Green Infrastructure Methods 6.3 Methods of Reconnecting Fragmented Spaces 6.4 Critical Issues of Site 7. Design 7.1 7.2 7.3 7.4
Modified Tp Scheme Master Plan Master Plan Sections Master Plan Level Guidelines
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Contents 8.
Demonstration Area
8.1 Demonstration Area on Master Plan 8.2 Soil Sampling Analysis 8.3 Analysis 8.4 Concept 8.5 Detail Plan 8.6 Views 9. Conclusion 9.1 9.2 9.3
Larger Vision- Community Spaces Larger Vision- Regional Spaces Outcome
References 10. Annexure 10.1 Regional Layers 10.2 Plant List 10.3 Quadrat Study 10.4 Seminar
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I
Introduction
The intent and vision of the project is described, underlining the need of the study through the lens of disturbed ecologies in cities and their need for revival and involvement in cities.
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Natural Systems
Impact of Cities on Natural Systems
From purifying water to pollination, nature is always on the move, from a sapling to a trees death it performs all its activities while also supporting the surrounding ecosystem and being a part of the natural cycle.
As villages slowly grew into towns and ultimately cities, the relationship villagers had with their surroundings also started to change. In a village, people used to depend on their livestock for daily goods and cultured a bond with the cattle, wildlife and vegetation around them. Even the relationship with the flora of the place was unique in its own context which was one of give and take between them. The people understood the trees needs while also developing the skill to harvest parts of the plant, crop, or tree. They knew the uses of each species; it was a home to local wildlife, helped in firewood collection, water percolation, protection of top soil and created cool micro-climates. This intimate setting provided hands on experience of the benefits of nature while at some level still maintaining the integrity of the system. The open spaces and scrubland pockets were used for collecting resources not easily available elsewhere, and also allowed the ecology to flourish. This human nature contact created a bond where both could thrive simultaneously.
Every individual species of flora and fauna are important with their respective roles in a natural system. They manage the resources efficiently and keep the ecological footprint in check. The natural system finds balance in nature and keeps earth a cool and stable place.
Benefits of Ecosystem Services Natural systems provide a number of untold services both tangible and intangible. These resources are of very high value to
With the onset of expansion due to provision of infrastructure facilities, the transparency of the natural working system between humans and nature slowly ceased to exist in large cities. More of the natural layers were removed to make space for a more faster and efficient means of development, leading to loss of management of natural resources. Exploitation of these resources led to reduce in resilience of the ecosystem and had many drawbacks of equal importance on both fronts. The overutilization also fractured the capacity of the natural system to heal and perform functions resulting in loss of wildlife, water, degradation of vegetation amongst others. Even cities faced problems such as reduction in health, pollution on various fronts, natural calamities such as flash floods, and problems relation to urbanisation like the heat island effect.
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As a result of creating breathing pockets in cities, urban parks and gardens have been developed in cities over the last hundreds of years. Genuine efforts have been taken to create a better lifestyle for its citizens although the amount of space allocated for such places seems to be a bare minimum, as they are not considered places of economic development. Natural open spaces are given least importance and are mostly revamped for development creating setbacks and strain on ecosystems. While making changes in the heart of the city might prove challenging, steps can be taken to ensure that future development of cities can happen in accordance with the natural layers of the region. This would help both the city and preserve the local ecology of the place. When a few ecological factors are considered during the development of cities, it can benefit mutually and help create a balance which was long lost in the process of modernisation.
Ecological Conflicts Conflicts in the environment happen at each and every level of magnitude, most of them are self-resilient, but a few places are over-exploited to the point that they are unable to revive themselves. Most of these conflicts tend to happen in and around cities.
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Most of the ecological effects in cities can be categorized: 1. Habitat loss - Construction of roads and railroads, physical encroachment of land gives rise to disturbance and barriers that contribute to the overall habitat fragmentation due to infrastructure. 2. Disturbance - Construction and traffic disturb and pollute the physical, chemical and biological environment and consequently alter habitat suitability for many plant and animal species. 3. Alterations - Other flora and fauna species which are not native to the land adapt and change the ecology. 4. Barrier - For most non-flying terrestrial animals, infrastructure implies movement barriers that restrict the animals’ range, make habitats inaccessible and can finally lead to an isolation of populations. The barrier effect is the most prominent factor in the overall fragmentation caused by infrastructure.
Fragmentation As Ahmedabad grows, the effects of urbanisation take away the natural layers present in the city. The water systems which fed water to the river, the population of flora and fauna which supported each other and the environment, have all been slowly exploited and diminished to a few small pockets unable to co-exist due to roads and buildings severing their link with the surrounding environment diminishing its importance.
Vision To Re-establish a city’s existing ecological structures and lost connections and reinforcing the usefulness of such systems into developments by integrating blue green infrastructures and management guidelines which can change the tide of urbanisation. While the pressure of urbanisation is on the rise, the loss of biodiversity and nativity of the place is gone along with its interactions. Articulating the need of such resources in cities and displaying its benefits would help in the restoration of the nativity of the place. Key Words Ecological Systems, Native Flora, River Habitats, Diversity, Preservation, Regeneration
Aim Envisioning an ecological system of connectedness in peri-urban areas of the city using tools of green/blue infrastructure.
Objectives • To integrating existing ecological systems into the urban fabric • Resolve the fragmentation in the city though connective green networks • Restore the connections to the natural surroundings • Bring back the lost biodiversity and nativity of the city • Address and reduce the problems arising in cities due to unplanned development • Creating interactions between humans and their natural surrounding
Methodology • Study the existing green pockets • Choosing a study area based on existing ecological systems integral to a larger network • Studying the ties of existing villages/Land use and proposed development • Making guidelines to incorporate the ecological diversity of region • Similar guidelines can be followed throughout the city for increase in canopy cover/green networks • Infusing design guidelines to enhance biodiversity and nativity of the place • Integrating green infrastructure into peri-urban regions • Demonstrating a model area where development and ecology can co-exist together
• Increase the canopy cover of the city
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II
Ahmedabad
Ahmedabad was chosen as the study area to understand how the growth of the city lead to the fragmentation of its natural layers and the statistical data of greens of ahmedabad, existing and required.
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Statistics of Greens of Ahmedabad Definition of Green Space in Ahmedabad as per AMCParks, Gardens and Open spaces As per the statistics of AMC the parks and gardens withing the city limit is as mentioned : Parks and gardens = 748.8 hectares = 1.6% of AMC area = 1.33 sq m per person
Source : https://www.researchgate.net/publication/254442295_Analysing_evolution_of_urban_ spatial_structure_a_case_study_of_Ahmedabad_India/figure
Defining Greens of Ahmedabad
Ahmedabad is a city which has developed around a river and is the biggest city in Gujarat constituting of 464km2 at an elevation of 49m from sea level with a hot and dry climatic zone. As per the thesis entitled ‘Exploring the potential of green infrastructure of Indian cities- a case of Ahmedabad city’ by Sonali Anusree, Ahmedabad has 1.6% of green space which is also in accordance with the AMC (Ahmedabad Municipal Corporation) as of 2014. This constitutes of about 1.34m2 per person while the WHO guidelines is 9m2 per person, required amount of green space in cities.
Whereas the required amount as suggested by WHO guidelines = 9 sq m/person Hence we can see there is a wide difference in the amount of natural space which is required and which is existing. The figures below would elaborate of the green spaces of the city.
Green spaces are defined as the parks, gardens and other open spaces within a city. While in general there is a larger definition to the types of greens. AMC * AMC prepared its Principal DP in the year 1965 and revised it in the year 1983. * AUDA prepared its Principal DP in the year 1987 and revised it in the year 2002
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Chronology of Ahmedabad
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Source: Maps from Regionals Group Work
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Fringes Extent of Fringe
Ahmedabad Municipal Corporation (AMC) consists of -191 km2. The area beyond the city’s municipal boundary of, which is experiencing high growth pressure, consists of forty-seven census wards -319 km2. This peripheral area together with the AMC is known as the Ahmedabad Urban Complex (AUC) area.
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Extent of Change
The black places indicate the severity of the change in the city and it is majorly attested to the extreme east and west ends of the city. The sub-urban have been recently taken into the municipal area and a major concern to the ever decreasing green spaces.
Growth in Fringes- 2000-2020
Conflict Areas of Ahmedabad
This map shows the growth of how the city has expanded in 20 years in the zones of the AMC and AUDA boundaries. A lot of open spaces have become a part of the development and have become lost, scarce or degraded. The red square is the chosen area of study and implementation of various methods to reconnect the green spaces.
Conflicts arise mainly due to the encroachment of spaces.
Actions needed to be taken in response to fragmentation: * Protect existing high-quality wildlife green spaces. * Manage and improve degraded green spaces. * Restore sites of particular value that have been destroyed. * Improve the permeability of land use between sites. * Create new green spaces.
* Roads destroy majority of watersheds, streams and rivers. They alter the course of many of the smaller water systems due to the height in which they are constructed and also as provisions are not made to allow these small water systems to cross. * Water bodies have dried up, been flattened out for development or converted into artificial lakes which do not get recharged by nearby percolation. * Degradation of green spaces and open areas are a few of the reasons for their disappearance. * Developments happening on the land cause problems to many of the surrounding areas and pollute the air, land and water nearby. 17
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Site Introduction
The Site is located in the northern part of Ahmedabad. It is under the Development plan of 2021 and has one of the last existing natural streams leading to the river and riperian edges.
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Larger Context
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Site Justification
Positive Characteristics -
Negative Characteristics-
* Natural river banks present * Upstream, continuous and clean water from Narmada Canal * Can sustain diverse habitats due to supply of water * Close proxmity to Cantonment which is rich in biodiversity and vegetation * Good connectivity of roads and railways connecting all parts of city * Close proximity to city center and airport * Existing ecological hotspots can be preserved and integrated * Social and cultural markers present around site
* Sewage is released into the river * Roads play a big role in cutting off water systems * Outside the AMC boundary, haphazard development * Streams connected to larger water system disrupted * Existing ecology in degraded state
First Impression of Site
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Larger Context - Sabarmati River Ecology
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IV
Site Analysis
This session elaborates on how the site has evolved from 1954-2019, along with its various natural layers of flora, fauna, elevation, TP Scheme and how the development has modified the natural layers.
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Chronology and Potential of Site
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Ecological Habitats on Site
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Fauna
Babbler
Drongo
Bull, Cow
Egret
Ibis
Green Bee Eater
Boars
Snakes
Peacock
Black Winged Stilt
Black Ibis
Greylag Goose Sunbird
Mallard
Asian Spoonbill
Nilgai
Mongoose
Parrot
Bat
Wattle Lapwing
Kingfisher
Bulbul
Peahen
Hawk
Bull, Cow
Great Egret
Porcupine
Squirrel
Monkeys
Black Myna
Lapwing
Swamphen
Collared-Pratincole
Reed Wabler
Jacana 27
Issues on Site
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Narmada Canal
Sabarmati River
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Existing TP Scheme Proposal of 2021
Narmada Canal
Sabarmati River
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These are the proposed areas for the various land use.
Land Use Legend - Detail of Residential Zones
Total Area: – 17.2 sq km
Residential Zone I (R1):
Residential I- 1.8 sq km
The residential buildings in R1 zone can range from single residential unit per plot (i.e. bungalow) to multistorey high-rise buildings with multiple residential units in it. Permissible height = 70 mts.
Residential II- 5 sq km Residential III- 3.5 sq km Village Gams – 2.1sq km (.25 + .2 + .15 + 1.5) Agriculture – 4.75 sq km Institutional and Industrial – 1.5 sq km The Individual land use is taken into consideration and studied with suitability to the natural layers, through this we can understand the problems generated with the specific land use and its allocated areas.
Residential Zone II (R2): This zone also permits land uses similar to Residential Mixed Use Zone 1. The main difference is in the permissible FSI. Residential Zone III (R3): This zone is primarily the residential area in the city having individual housing such as like bungalows and farm houses. This zone also permits uses like education and cultural uses, party plots and public utility buildings.
Problems in Specific Areas 1. Residential zone 1 has been proposed over the existing scrub vegetation and stream which is a very important natural resource for the zone. 2. Existing stream has been disconnected by many perpendicular roads without culverts leading to blocks and clogging and foul smell due to stagnation. 3. The rich diversity on the river banks riperian edge including flora and fauna would be lost with the existing proposal in place surrounded by residential zones. 4. Topography and existing flow network has also been neglected while implementing this TP scheme. 5. Existing ash pond has not been considered into the TP scheme and has been labelled as residential though it makes up a good amount of green coverage for the nearby areas and is esentially a privately owned body.
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Impacts After 2000
1. Major environmental degradation starts around road fringes and expands inwards. 2. Sources of streams and rivers nearby led to more number of industries for easy disposal of effulents. 34
3. Large scale impacts of farmlands in the interiors being coverted into residential plots. 4. Growth of development is faster around the peripheral areas of the existing development
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Case Studies
Criteria of case studies was based on a range of types, one on how the degraded natural systems in cities were bought back, another on how they integrated the development with natural layers, one on small scale pocket places and another on how management of such integration in Indian systems can be achieved. 35
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VI Design Development
With the inferences from case studies on how different ideologies worked within the city, few types of methods of blue-green infrastructure, connections for fragmentation and urban and green edges were explored to restore the links in the city. 44
Systems Diagram
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Blue Green Infrastructure Methods
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Connecting Fragments
Existing fragmentation in the cities, which once was a whole system of larger edge condition and core.
Preserving and reconstructing the edges of the fragmented natural open spaces in cities .
Linking these existing pieces and creating community natural spaces which will support the existing systems.
Developing connections through urban parks and gardens to increase the number of alternate corridor passages to the core, which intern strengthens the movement and diversity of the fauna species. 47
Critical Issues of Site
Narmada Canal
Sabarmati River
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VII
Design
By modifying the TP Scheme a more detail design was established which had the benefits of the natural resources. Guidelines at various scales for the respective zone were given such that each scale responded to its environment appropriately. 50
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Modification of TP Scheme
Narmada Canal
Sabarmati River
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The amount of requirement under each land use remains the same, the modification only re-alters the area of the land-use to places suitable for each specification.
Types of Modifications
* Proposed area of residential areas are taken into account and rearranged at better zones such that both people and nature benefit from the re-arrangement. * Larger part of the residential has been allocated near the highways as development happens along the main roads before spreading inwards. * The highways are also located on the higher countours ridges and dont disturb valleys.
* These areas have been proposed as agriculture with a few minor adjustments or percentage of space allocation to allow the natural flow of water and other features like existing scrub vegetation to grow and develop at its own pace. * Ash pond being a government land can also be specified as private property with restrictions on construction.
* Proposed residential areas in these zones have been reallocated at different places. These were few of the factors considered to remove residential areas in these zones: * rich resource potential * have diverse habitats * has a stream connecting to the river * flood zones * good quality soil * larger green network * existing green cover 53
Master Plan
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Master Plan Legend
Refer to the Annexure for Deatil Plant List of the Master Plan. 55
Master Plan Sections
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VIII
Demonstration Area
While the subject was explored at a larger scale, a smaller area was chosen so that site specific problems and issues can be addressed through the various methodologies mentioned.
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Demonstration Area on Master Plan Demonstration area is located next to the koteshwar village on the banks on the river as it displayed a potential. It had already been degraded by development and the natural edges still existed without being completely eradicated. It was also seen as a zone which was fast developing with new roads and buildings coming up all around the area, without any respect or response to its surroundings. This place was also in touch with their local surroundings as people from the village daily into the scrubland daily for various purposes like collecting firewood, and the integrity with their lifestyle and use of natural resources still existed. Existing wildlife is very diverse around this place and neelgais have its own corridors running along the scrubland.
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Analysis of Area
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75m
225m
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- Boardwalk Next to Stream
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- Urban Park
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Conclusion
Projected outcome and future implication of the design interventions in an urban fabric over the course of time and how natural systems and development mutually benefit each other.
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Open Pocket spaces next to residential communities 74
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Conclusion
At various levels of the city , if we establish a systems of pocket spaces and green networks throughout the city along with sustainable building techniques and environmental friendly materials and methods of construction, the developing city as a whole can find a vast difference in the health of the people and the environment. The natural systems can better thrive in such circumstances where it’s given due importance.
The transparency of the systems in terms of how the natural layers work, from the water bodies, to the wildlife and flora can help create an understanding on how they actually help in curbing the heat-island effect of the cities, its pollution and implications of such on the environment. These systems also display the effective management of water percolation throughout the year to flood regulation at monsoons. 77
References Statistics of Ahmedabad * https://www.researchgate.net/publication/254442295_Analysing_evolution_of_urban_spatial_structure_a_case_ study_of_Ahmedabad_India/figure * Evaluating the Urban Green Spaces: Benefits and Issues, 1Ar. Mohd. Shoeb Jafri, 2Ar. Mohammad Rajaullah, Dr. D Y Patil College Of Architecture, Akurdi, Pune, India * Smart Green Urbaniam: Ahmedabad City’s Perspective , Arnab Sen1 and Prerona Mukherjee2 1,2, Architect, Urban & Regional planner CEPT UNIVERSITY * Analysing evolution of urban spatial structure: a case study of Ahmedabad,India Article in Environment and Planning B Planning and Design · September 2011 * Thesis ‘Exploring the potential of green infrastructure of Indian citiesA case of Ahmedabad city’ Sonali Anushree, 2014 * Status of Tree Cover in Urban Areas of Gujarat, Gujurat Forest Department-2010 * UDPFI- Urban development plans formulation and implementation * AMC- Ahmedabad Municipal Corporation * AUDA- The Ahmedabad Urban Development Authority Case Study 1 - Nantong Eco-Corridor * https://landezine-award.com/nantong-eco-corridor-phase-1/ * https://www.aecom.com/projects/nantong-eco-corridor/ Case Study 2 - Qian’an Sanlihe River Ecological Corridor * http://landezine.com/index.php/2012/01/ecological-coridor-landscape-architecture/ * https://www.asla.org/2013awards/062.html * https://land8.com/from-neglected-to-extraordinary-the-story-of-the-qianan-sanlihe-greenway/ Case Study 3 - The Metro-Forest Project LAB Landscape Architects of Bangkok * http://landezine.com/index.php/2016/07/metro-forest-bangkok-urban-reforestation-by-lab/ * https://landscapearchitecturemagazine.org/2017/05/08/control-of-the-canopy/ * https://land8.com/bangkok-gets-reintroduced-to-nature-and-results-are-spectacular/ Case Study 4 – Adyar Eco Park * http://tnuifsl.com/crrt/adyarcreek-1.asp * http://www.pitchandikulamforest.org/PF/adyar-eco-park/ 78
TP Scheme * http://www.auda.org.in/RDP/ Fauna of Spotted Birds * http://birdsofgujarat.co.in/district_bird_list.php?list=Ahmedabad * http://birdsofgujarat.co.in/checklist.php * https://www.explorewithecokats.com/birdwatching-destinations-around-ahmedabad/ Climatic Data https://www.meteoblue.com/en/weather/historyclimate/climatemodelled/ahmedabad_india_1279233 Sabarmati River * https://en.wikipedia.org/wiki/Sabarmati_Riverfront * https://economictimes.indiatimes.com/news/politics-and-nation/the-transformation-of-sabarmati-from-aparched-riverbed-with-puddles-of-industrial-effluents-to-a-bustling-swanky-riverfront/articleshow/45998310.cms * http://twocircles.net/2014apr29/untold_story_behind_sabarmati_riverfront.html * http://sabarmatiriverfront.com/regional-history Greens of Ahmedabad * https://ahmedabadcity.gov.in/portal/jsp/Static_pages/citizen_Municipal%20Parks.jsp#northZoneList * https://ahmedabadcity.gov.in/portal/jsp/Static_pages/garden_dept.jsp Green-Blue Infrastructure * Low Impact Development/ Green Infrastructure/ Best Management Practices-Hudson county planning board.pdf * Green infrastructure: concepts, perceptions and its use in spatial planning by Ian C. Mell, June 2010 * Wetlands of Gujurat, Dr. H. S. Singh, IFS, Chairman, Gujarat Biodiversity Board Plant List * Observations along sabarmati River, Landscape Environment Advancement Foundation, LEAF * An Enumeration to the plants of Ahmedabad and Gandhi Nagar, Gujurat, S.L. MEENA Botanical Survey of India, Arid Zone Regional Centre, Jodhpur - 342008, Rajasthan. Google Maps- Google Earth Pro
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Annexure
It encompasses the various natural layers of regional study done as a group work by everyone in the studio with the Plant list for the design of the project. A Quadrat study excercise and its learnings along with the seminar conducted by individual students in the course of the studio. 80
Regional Layers
• Generating different layers of regional maps help associate the cultural and ecological aspects of the ever changing region and its landscape. For examplepresent and past landscapes, land use, soil formation, geology are a few important factors required for future planning. • The city has mostly grown along the Sabarmati River, settlements coming up near water bodies, and the junctions of the main roads due to ease of access. Elevation Map
Hydrology Map
Soil Map
Geology Map
• Contours- We can also see through the contour lines that the northern part of the city lies in the higher contour elevation while the southern part has the lower contour elevations roughly varying from 25m in the south to 75m in the north for a distance of approximately 45km, making it an almost gradual slope of 1:1. • Hydrology- • The river has under grown a huge change in 2012, when the riverfront project got inaugurated through the city area on Sabarmati River, transforming a once perennial river which had become a seasonal river into a perennial one again. • T h e drainage pattern along the riverfront development has been diverted to Vasna barrage. Upstream, which is not connected to the riverfront still discards waste water directly into the Sabarmati River. Black colour water is emitted from the waste water treatment plants downstream of Vasna barrage. • Soil- The region is made up of Loam soil- composed mostly of sand, silt, and a smaller amount of clay, which is further classified into coarse, fine alluvial and fine soil. It also has a slight tint of saline soil. Almost 65% of the region has very deep soil, 25% has deep soil and 10% has moderately deep soil. • Geology- The region can be divided into four geological zones- 60% of continuous alluvial plains along the Sabarmati river, 25% of Sand sheets and sand dunes(formed by wind depositions during arid phase) towards the drier areas of Ahmedabad, 10% of tidal flats(formed by deposition of sea sediments) and 5% of conglomerates (limestone and sandstone). 81
Regional Layers
• Ahmedabad maps of 1954, 1974, 2010 and 2019 were taken to compare the transition of the urban growth and its impact on vegetation and water bodies.
1954 Map
1974 Map
2010 Map
1954 - • Tekras and talavadis dot the area around the walled city and the peripheries leading to small dry hills and water collection points. • The villages each had their own source of water body nearby and were self-sufficient in terms of water supply. Agricultural fields were irrigated with canals. • Ahmedabad walled city was the main extents of the main city. 1974- • Tekras and talavadis within the city limits were converted to flat surfaces for better construction, causing imbalance in the system of flowing water. • Most of the development took place near the water bodies and streams, using them as markers for city limits. • The agricultural fields around the Sabarmati in the outskirts changed land use for development of the city. • The AMC boundary extended outwards on all sides by 1974. • AUDA boundary was established in 1978. • Settlements started appearing on the sides of major roads. 2010- • Lakes could not self-sustain themselves as embankments were built and drainage systems altered in the surrounding areas leading to drying up of lakes. • Quality of water has decreased with pollution, and other factors. • Water from the Narmada Canal started feeding the Sabarmati River from April 2008. • Many of the natural green spaces in the fringes have been overturned for expansion. • Brownfield sites and vacant plots are a regular sight along the borders of the city. • Industrial growth in nearby areas, denser city centers. 2019- • A number of canals have opened, made of concrete. • Ravines have been filled up and flattened. • Scrublands are encroached for development of human settlements. • Parks and Gardens developed in city. • Finger like projections can be seen in the cities development along the major roads. • Railway lines and Metro lines have also extended.
2019 Map 82
Regional Layers
• Land Use- Ahmedabad city is surrounded by an extensive agricultural area and lies on the banks of the Sabarmati River. • The city has spread to about 400 sq. km on either side of the river. Almost 50% of the city is covered with built ups, Recreational spaces are less than 3%, Industries, Institutes and Commercials total up to approx. 15-20%, Barren land approx. 15-20% and Water bodies approx. 15%. Land Use Map
Ecological Conflicts Map
• AMC, AUDA boundary- In 1954, the extent of Ahmedabad was only the old city, which by 2019 has grown to about 30 km from the city center. The AUDA boundary has extended over Gandhinagar in North and beyond Sher Talav in the South. • Ecological Conflicts- Conflicts happening due to development of infrastructure and roads on the surrounding environment, altering, damaging, or completely changing the various open spaces and water bodies present in the city. Changing topography of the land or doing landfill using ash from the power plant. Drastic modifications have been creating conflicts on the environment.
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44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
Shrubs Acalypha indica Alhagi pseudalhagi Anisomeles indica Barleria priontis Caesalpinia crista Capparis sepiaria Cassia angustifoilia Cassia auriculata Cassia tora Clerodendrum inerme Euphorbia nerifolia Jatropha curcas Kirganelia reticulate Maytenus emarginata Ocimum basilicum Plumbago capensis Plumbago zeylanica Phyllanthus fraternus Saccharum spontaneum Sesbania bispinosa Tamarix ericoides
Common Name Indian Copperleaf Camel Thorn Indian Catmint Porcupine flower Crested Fever Nut Wild Caper Bush Alexandrian senna Tanner's Cassia Pot Cassia Glory Bower Indian Spurge Tree Physic nut Black-Honey Shrub Thorny staff tree Basil Plumbago Chitrak Gulf Leaf-Flower Kans Grass Prickly Sesban Erica Tamarisk
Use
P/A P/A P A P P P P P P P P P P P A P P A P A P
Height upto 60cm upto 1m 1-2m 1-1.7m 10m 1-2m 1-1.5m 1-1.5m 1-1.5m 1-3m 3-5m upto 3m upto 4m Upto 3m upto 60cm 1-4m upto 1m upto 80cm .5-1m upto 3m 2-4m
65 66 67 68 69
Aquatic Plants Hydrilla verticillata Lemna gibba Nymphaea pubescens Trapa natans Typha angustata
Common Name Hydrilla
Use
P/A P
Height 5-50mm
P P
15-26cm 2-3m 2-3m
P/A P P P
Height upto 1m upto 1.2m 1-2m
Grasses 71 Hemarthria compressa 72 Paspalidium geminatum 73 Oryza sativa
Pink water Lily Water chestnut Narrowleaf cattail Common Name Whip Grass, Jove grass Egyptian Panicgrass Asian rice
Use
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Infrences * It is one of the simple methods to identify and quantify the type and number of species and calculate plant population frequency, density. * Extent of the plant growth through physical conditions like the soil, water, sun, shade, and fauna of the local context. * We can see how one species influence the growth of other species or the other factors of flora which stimulate growth patterns in respective areas. * In ground cover study we can understand how the seasonality of the trees affects the soil condition and nourishment and if small plants grow in such conditions or are barren.
* If we remain for a longer duration then the animals and its general movement may be exposed. * It helps us make the necessary assumptions about the habitat and to generate future predictions about the stipulated growth of the area with respect to its flora. * Compare the sub-areas within the total zone of study to understand patterns and language. * Technique for canopy structure and light penetration interpretations lies in the long time to establish accuracy. Hourly changes in light penetration characteristics may help in the study. * Distribution of wild plants in the zone through the ground cover study. 87
Seminar - Urban Forestry Define it ? An urban forest, is the trees and related vegetation in and around the city. A multi-disciplinary activity that encompass the management of trees, woodland and associated area and open space, linked to the mosaic of vegetation in a built area for the promotion of human well-being. Their natural diversity and their interconnectedness with human activities and the built environment make urban forests both complex and dynamic. It is the care, maintenance and management of single trees and tree populations in urban settings for the purpose of improving the urban environment. Distribution : It includes all woody vegetation within the environs of all populated places. Trees within cities, associated lands – e.g. Greenbelts, municipal watersheds, recreational sites, roadsides. Scope: Avenues, Parks and Gardens, Industrial shelter belts, wildlife parks, abandoned, brownfield sites, wilderness trail, botanical gardens, public and private properties. Importance in Urban Settings Improved air quality: Leaf surfaces are able to trap and absorb noxious gases and particulates. This can go a long way towards alleviating our increasing problems with smog. Energy moderation: When properly planted and selected, trees can provide energy savings year-round. In the summer, trees provide shade and shelter from the heat. In the winter, when the leaves have fallen, the tree allows sunlight to pass through, while providing added protection from the cool winter winds.
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Temperature management: Trees in urban settings are able to buffer extremes in temperature. The shade provided by the trees prevents the infrastructure from absorbing heat, and trees transpire large quantities of water on a daily basis, which cools the ambient air. Property values and aesthetics: Not only do trees make the city a nicer place, they also increase property values. In some cases, it is estimated that property values may increase by up to 25% in a well-treed neighborhood. Noise pollution: Trees can buffer city noise, reducing overall noise pollution. Planting a row of trees between residential properties and a highway is an effective way of reducing noise. Storm-water reduction: Urban forest canopy directs rainwater from streets, into the ground. This enables water filtration through the soil, resulting in cleaner water and less water damage to city infrastructure. Wildlife habitat: There are many different organisms that rely on our urban forest for life. Everything from microorganisms to birds and deer rely on our trees for shelter and food. Physical and psychological well-being: Studies have proven that trees are good for your psychological wellbeing. Not only are you likely to recover more quickly from an ailment in a treed environment, but studies also show that tree neighborhoods have reduced crime rates. “ Urban forests cannot be defined along one dimension and can be measured with regards to their Ecological complexity. Complexity in terms of undergrowth, natural regeneration, crown cover, suitability to wildlife. It also increases as it moves away from the urban environment. Urban forests can only be understood only by analysing the following factors Community infrastructure, human population density, size of parcel, ownership and social characteristics off associated human population. “
Composition of an Urban Forest
Environment for the Urban Forest
Is primarily influenced by physical elements and keeping in mind the plant hardiness zones. Factors often interrelated are also through:
Physical environment - Construction in cities influences existing setting changing grades, drainage, soil, surfaces and air patterns.
Purpose of function – Eg. Shade, wind, screening, produce, etc.
Space - Critical factor limited by physical elements such as buildings, roads, utilities, line of visions, signs and street lights, vistas and clearance. Its requirments based on height and tree form.
Popular species- Practical reasons of form and strength, local availability, maintenance Public control- Planting programs influence composition of forest. Composition also depends upon legal factors of urban development. Socio-economic factors- low resident income- declining old trees remains of “wooded fringes”, middle and upper class- trees tended, natural woodlands found. Mobility- temporary location for residents- least interested in planting trees, ownership of land for long term- plant trees Nostalgia- feeling of familiarity and profound influence of one’s landscape.
Soils- Drastically altered due to construction, top soil removal, compaction, drainage restriction or changes in water table, i.e. Sand, rubble, debris, chemicals, waste. Topography - Particularly at extremes to flooding and steep slopes to erosion and high elevation where climate influences are critical. Micro-climate- Microclimate factors having influence on tree growth are air temperature, humidity and wind. Pollution : Air, Soil, Light- Physical pollutants: heavy dust on stomata’s and restricting respiration. Chemical pollutants: physical damage or impact chemical processes of plants.
Benefits of an Urban Forest
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