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And Management of Progressively Altered Landscape Case: Sopara-Bolinj creek, Vasai-Virar, Maharashtra

E C O L O G I C A L S T U DY O F A T I D A L C R E E K


E

COLOGICAL STUDY OF A TIDAL CREEK

And Management of Progressively Altered Landscape Case: Sopara-Bolinj creek, Vasai-Virar, Maharashtra

Shraddha Sawant LA9812

Shraddha Sawant LA - 9812

Department of Landscape Architecture, C.E.P.T University

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MASTERS PROGRAM IN LANDSCAPE ARCHITECTURE FACULTY OF ARCHITECTURE CEPT UNIVERSITY AHMEDABAD CERTIFICATE

This is to certify that the thesis titled:

“Ecological study of a Tidal creek & Management of progressively altered landscape: Case – Sopara-Bolinj creek, Vasai-Virar, Maharashtra” Submitted by : Shraddha Sawant(LA8711) Is in partial fulfilment of the requirement for the award of Masters Degree in Landscape Architecture This is a bonafide work done by the student and has not been submitted to any University/ Institution for award of any Degree/ Diploma. Date :21st Sept, 2014 Guided by: Prof. Prabhakar B. Bhagwat Professor

Prof. Dr. Deepa Maheshwari Professor and Program Coordinator

Prof. Sandip Patil Assistant Professor

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Acknowledgement I take a chance to formally acknowledge the contribution of all those who have been a constant source of inspiration to me during my research work.

To begin with, I wish to express my sincere gratitude to Prof. Prabhakar B Bhagwat, Dean, Faculty of Landscape Studies, CEPT University, for his belief in me and his invaluable guidance in providing the right direction to the thesis. Also for helping me gain interest in history of the place. I have reflected his experience and minute observations here, in the study. I express my intense gratitude towards Prof. Dr. Deepa Maheshwari for her constant guidance. She provided extremely useful references and gave me an in‐depth understanding of my thesis. Without her, the detailed analysis undertaken during the study wouldn’t have been possible. I would also like to thank Prof. Sandip Patil for his help, suggesting relevant case study examples during the discussions. A heartfelt thank you, to Prof. Madhukara his ever‐available advice and initial discussions which helped me in understanding the Geology of the study region.

I acknowledge the affectionate cooperation and support from all LA friends and juniors. I am indebted to my roomies- Prachee, Ravnish and Manasi for the motivating discussions, sleepless nights, and for all the fun we have had in the last two years. Above all, I thank my parents for all their patience, support, love and motivation throughout the course. Shraddha, January, 2013

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Content List of figures Abstract Introduction

Associated values of the landscape 1.1. Location and Economic values 1.1. 1 Fishing 1.1.2 Crops 1.1. 3 Vegetables 1.1. 4 Horticulture 1.2. Ecological values 1.3. Scenic value

Premise of study- Coastal mudflats 2.1 Aim 2.2 Objectives 2.3 Methodology

The Study region

3.1. Base map 3.2 Defining the study region

About the Study region 4.1. About the Region 4.2 Climate 4.2.1. Rainfall 4.2.2. Temperature 4.2.3. Humidity 4.2.4. Winds 4.3 Tidal data 4.3.1 Wind direction 4.3.2 Currents

Elevation

5.1. Elevation map

Land-Use of the study Region 6.1 Extent of Urbanisation 6.2 Urban character

Chronological evolution of the study Region – Natural history 7.1.1 7.1.2 7.2.1 7.2.2 7.3

Political changes in 7th century Physical changes in landscape Political changes in 18th century Physical changes in landscape Inferences

Analyzing natural resources in the study region 8.1. Soils 8.2.1 Geomorphology 8.2.2 Geology

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Content Instability of Natural resources- Analysis 9.1.1 9.1.2 9.2.1 9.2.2 9.3. 9.3.1 9.3.2 9.3.3 9.4

Ground water Recharge Potential Inference Cultural practices of the coastal villages A portion of the site, along the coast still remains a village Factors affecting coastal villa Salinity ingress Traditional shallow water wells ‘bhowkals’ Tube wells -reducing the functioning of traditional wells Conclusion

Issues of the region 10.1.0 10.1.1 10.1.2 10.2

Tidal creek- an estuarine ecosystem Imbalance in water entering the tidal creek inlet from sea Imbalance in fresh water entering the tidal creek due to runoff Further focus areas for analysis

Analysis of the issues

11.1. Ecotone map – Habitat for migratory birds 11.2 Ecotone 1 11.3 Ecotone 2 11.4 Ecotone 3 11.5. Graph showing no.of Winter migratory, Resident, local migratory, Monsoon migratory and Post- monsoon migratory bird population of site as per International Journal of Advance research 11.7. pie chart showing no of threatened, Critical, vulnerable to extinction and least concerned species near Bassein fort area as per International Journal of Advance research 11.11. Salinity affected areas 11.12. Zones based on causes of salinity & areas for surface water detention 11.13. Representative sketches showing reason for salinity, waterlogging and inadequate tidal flow. 11.14. Proposed diversion to reduce waterlogging in low lying areas 11.15. Process of leaching out salts from salinity affected area

Land Suitability

12.1. Schematic section of drain fields 12.2. Process of leaching out salts from salinity affected area 12.3. Proposed location of water bodies on site 12.4. Proposed plan

Proposal

13.1 Tidal creek restoration 13.2 Land suitability for agriculture

Conclusion

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List of figures Fig.1.1. Fig.1.2. Fig.1.3. Fig.1.4.

West coastline of India Graphical representation of site and its Scenic qualities Locational value Ecological value

Flowchart.2.1 Estuarine mudflats and arising conflict area Flowchart.2.2. Ecological v/s Economical values of coastal mudflats on site Fig.3.1. Base map Fig.4.1. Graph indicating distribution of rainfall Fig.4.2. Graph indicating annual temperature Fig.5.1. Elevation map Fig.6.1. Land use plan

Fig.7.1. History map of ancient Sopara port location Fig.7.2. Map of Nirmal - Gaas area from Archaeological Survey of India, Western Circle- Progress report, 1898 Fig.7.3. History map of Portuguese fort location Fig.7.4. History map of Maratha territorial extent Fig.7.5. Current land use Fig.8.1. Fig.8.2. Fig.9.1. Fig.9.2. Fig.9.3. Fig.9.4. Fig.9.5. Fig.9.6.

Soil map Geology and Geo-morphology map Analysis map-Ground water recharge potential Geological section of coastal deposition Google imagery of coastal village Land-use map of coastal village Geological section of aquifers Schematic section of cone of depression

Fig.10.1. 7th century- Representative sketch showing dense forest around the tidal creek Fig.10.2. 16th century-Representative sketch showing forest conversion to Agriculture and slow process of siltation Fig.10.3. 19th century- Representative sketch showing mudflat reclaimed to salt pan and blocking of tidal flow in the estuary causing water imbalance Fig.10.4. 21st century-Representative sketch showing choking of tidal water leading to waterlogging in the city. Fig.10.5. Section showing process of churning of sediments during flood tide and slow deposition during ebb tide Fig.11.1. Ecotone map – Habitat for migratory birds Fig.11.2. Ecotone 1 Fig.11.3 Ecotone 2 Fig.11.4. Ecotone 4 Fig.11.5. Graph showing no.of winter migratory, Resident, local migratory, Monsoon migratory and Postmonsoon migratory bird population of site as per- International Journal of Advance research Fig.11.6. Photographs of spotted bird species as per the report of International Journal of Advance research Fig.11.7.Pie chart showing no of threatened, Critical, vulnerable to extinction and least concerned species near Bassein fort area as per International Journal of Advance research Fig.11.7. Water movement during low tide Fig.11.8. Micro catchments of the creek Fig.11.9. Drainage network Photographs Fig.11.10. Photographs of reclamation and embankment on the site blocking the tidal flow Fig.11.11. Salinity affected areas Fig.11.12. Zones based on causes of salinity & areas for surface water detention Fig.11.14. Proposed diversion to reduce waterlogging in low lying areas Fig.11.15. Process of leaching out salts from salinity affected area Fig.12.1. Fig.12.2. Fig.12.3. Fig.12.4.

Schematic section of drain fields Process of leaching out salts from salinity affected area Proposed location of water bodies on site Proposed plan

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Abstract IN THE GEOLOGICAL TIMELINE The West coast of India is defined by a narrow strip of land between the Western Ghats and the Arabian sea extending from Gulf of Kuchchh in North west to Kanyakumari in Southern tip of India. The west coast of India for many centuries had been an important trade route nearly 2500 years ago. During this period (Holocene period as per geological timeline) there has been a drastic sea level and resulted to shoreline shift. The ancient port sites along the west coast of India are Dahanu(72 43’E, 19 58’29’’N), Sopara(72 48’E, 19 24’N) and Chaul (73 E, 18 30’ N) The west coast is divided into 4 parts. Geologically the Konkan coast in west India is particularly formed by deposition of tidal clays, mendha, sand, dune complex rock of 510 m thick. These deposition is mostly confined to areas 6km inland from present coast.

Fig.1.1. WEST COASTLINE OF INDIA Source: Landscape Architecture in India-a reader Journal of Landscape Architecture

COASTAL LANDSCAPE OF KONKAN Going back to geological history of this area around 1200 years ago, there has been a change in coastal configuration. Most of the estuaries in the world that we see today were formed during this drastic sea level rise. The estuary formation along the Konkan is by normal depositional and erosional processes due to rise in sea level and not due to any tectonic activity. Depending of direction of sea current the coastal landform of Vasai- Virar slowly got carved out into bays, lagoons and tidal creeks. THE AREA OF STUDY – SOPARA , INDIA The area of study lies around the historic port town of Sopara, as mentioned above. Today this area is called Vasai-Nalasopara-Virar sub region. The coastal town of Sopara was internationally famous till 7th century. This area consist of a diverse physical, biological and cultural values. At a regional level, the landscape of this region is geomorphologically characterised by Tungareshwar hills, tidal flats, coastal floodplains ( converted to agricultural land), wetland in the centre of the city (converted to salt pan in today ), sandy shore and low height mangrove forest.

Today, the 7500 km of coastline of India supports 25% of the countries population. And occupies around 100km of coastline in total. The coastline also supports diverse habitats from mangroves, mudflats and marine species. The coastline is subjected to enormous pressure due to socio economic and anthropogenic factors.

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1.0.

Associated values of the landscape

1.1. LOCATION VALUES

AND

ECONOMIC

The Vasai-Virar Sub-region is separated from Greater Mumbai and Mira-Bhayander by the Vasai Creek. Location value directly correspond to time. The improved connectivity via Central and western railway line and bus facilitate shorter commuting time from Mumbai town to Vasai Virar. This has helped in decongesting the main city. The city is termed as the dormitory of Mumbai, resulting into unidirectional commuting during the peak hours. Although this has created a win-win situation because as the pressure on infrastructure in the main city reduced, the attractiveness of the suburban regions increased. Location value of the landscape due to its near proximity to the Metropolis has also impacted the real estate prices in both the main city of Mumbai and its suburbs. 1.1. 1 FISHING

Vasai is an important tehsil for marine fisheries, both urban and rural; estuarine fishing is negligible. It has a 22 km. coastline with 9 fishing villages and 5 fish-landing centres involved in marine fishing. The fishermen population of this area is around 15,000.

Fig.1.3. LOCATIONAL VALUE Source : BASE MAP- Google earth imagery

1.1.2 CROPS

The Paddy fields are all over the Vasai The eastern parts of Vasai Virar (at the foothills of Tungareshwar hill) mainly produces crops like rice, wheat, from the paddy fields where as the western parts was and is still known for its Coconut plantations, Bananas, Beetle leaves, In summer, the region produces vall, Tuar, Udit, Chavli, Maka etc in large quantities 1.1. 3 VEGETABLES

Farmers have been selling their vegetables in Mumbai since a decade. Brinjals, Tomato, Cabbage, Cauliflower, Lady Finger, Spinach and other leafy vegetables 1.1. 4 HORTICULTURE: Seasonal flowers like mogra, 'kagda' along with roses are grown

here and supplied to the Dadar flower market in Mumbai. Shraddha Sawant LA - 9812

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1.0.

Associated values of the landscape

1.2. ECOLOGICAL VALUES

Vasai lies on the north bank of Vasai Creek, part of the estuary of the Ulhト《 River. The salt pan land in Vasai and mangroves in Manori near Bhayendar, Mumbai act as dissipating grounds against the wave energy.

The city is located on the north bank of Vasai Creek, part of the estuary of the Ulhト《 River. The Vasai Virar Corporation Area is associated with diverse and highly productive ecosystems. It has vast stretches under wetlands, while the hills on the east are under forests, which are part of the Sahyadri. The sandy shores along the sea coast are linked to a marine ecosystem, and the inland waste bodies are part of a rich estuarine ecosystem, replete with mudflats, creeks and salt pans. Mangrove growth is prevalent along the major creeks and water channels where tidal effects are experienced.

Fig.1.3. LOCATIONAL VALUE BASE MAP- Google earth imagery Source: Author

Fig.1.4. ECOLOGICAL VALUE BASE MAP- Google earth imagery

These provide excellent habitats to a variety of organisms, including various species of benthos, fisheries and avi fauna. The birds migrate from the Rann of Kutch towards Mumbai in search of food on the wetlands of Mahul jetty, Sewri, Airoli and Vashi creek.

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1.0.

Values associated with the region

1.3. SCENIC VALUE

Scenic value is the primary indicator of the intrinsic scenic beauty of a landscape and of the positive responses it evokes in people. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Farmlands and distant view of hills Pastoral landscape Bird population on mudflats Sunset at Vasai beach Openness of salt pan areas Vegetable fields dotted with palm trees and banana plantation Mangroves thicket Road to the beach Flat lands Tungareshwar waterfalls Intertidal beach zone Patterns showing wave direction

Fig.1.5. SITE PHOTOGRAPHS

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2.0.

Premise of study- Coastal mudflats

Nowadays it is difficult to encounter a natural /virgin landscape. Most of the natural landscapes in todays date have been modified by human activities. Hence, they are embedded with several meanings and values which people assign to them. A ‘coastal’ landscape is generally governed by dynamic forces of nature. The processes of erosion and sedimentation, periodic storms and cyclones and sea level changes continuously modify the landforms.

Flowchart.2.1 ESTUARINE MUDFLATS AND ARISING CONFLICT

Man has utilized the immense resources of tidal flat in harmony with nature for thousands of years However, environmental changes by a very large scale of reclamation of coastal mud flat in recent years raises conflicts between conservation of the tidal flats and economic development by reclamation.

The mud flat, estuaries, salt marshes and their surrounding wetlands are the spawning grounds for fisheries, and they support coastal economic industries. Especially at high tide, the flats are important feeding grounds for fish and other wildlife. Also, estuarine mudflats, mangroves and salt pan areas are city’s last defence against ocean flooding. With economic growth and rapid urbanisation in past decades has seen the inter-tidal mud land, not as a natural resource, but as potential new land for economic development. A huge portion of mudflats have been reclaimed to salt panning years ago. In 2001, the development of Vasai-Nalasopara-Virar region along the Western Railway, about 50 km to the north of Bombay city become a highly controversial issue. The construction of the railway track on an embankment during colonial period ,2 to 4 m high seems to have choked the tidal flow, and brought about over time filling up of the depression. By then, the wetland was been completely transformed to a saltpan

Today due to the pressure of urbanisation, and strong intentions of the government, salt pan areas will be further reclaimed in Vasai. However, because of high salinity of the soil and the flooding risk it will face, the land cannot be directly redeveloped. ECONOMIC VALUE

ECOLOGICAL VALUE

MUDFLATS SPAWNING GROUNDS FOR FISH BY ADDING EMBANKEMNT OR LAND FILL

(MANGROVE HABITAT)

RECLAIMED TO SALT PANS RECLAIMED TO HOUSING

TODAY DECLINE IN SALT PRODUCTION IN THE CITY DUE TO LESS MARKET VALUE. HENCE IN FUTURE, GOVERNMENT PLANS TO RECLAIM SALT PANS FOR COMMERCIAL USE Flowchart. 2.2. ECOLOGICAL V/S ECONOMICAL VALUES OF COASTAL MUDFLATS ON SITE

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2.1

AIM:

The aim is to develop a land capability map for Vasai based on its ecological feasibility. And derive land suitability for future buildable areas within the constraint of estuarine hydrological network.

2.2

• •

OBJECTIVES: To conserve the stability of fragile ecosystem of estuaries and tidal flats To understand modification in prevailing cultural system and identify issues related to natural environment and sustainability of indigenous communities.

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2.3

Methodology Evaluating different ‘values’ people have associated to the landscape

Understanding natural evolution of the Creek landscape Process sedimentation and Erosion Premise of the study - Coastal land use conflict Evaluation of natural resources

Geology, Vegetation and Soil maps , Hydrology and Ground water resources

Identifying areas of Instability of natural resource Issues

Pressure of Urbanisation Salinity ingress in surrounding aquifers Upward movement of saline water Fresh water scarcity

Analysis

Areas undergoing inadequate tidal flushing Water logged areas / stagnation Reclaimed areas/ Embanked areas Identifying Eco tones Sedimentation and Erosion Suitability for mangrove regeneration

Land suitability

Future urbanisation Watershed management Future Land use for salt pan lands Suitable areas for mangrove regeneration

Case study- Thames Estuary Parkland Project details and Proposal

Proposal

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3.0.

The Study region

Fig.3.1. BASE MAP

Vasai 19ツー24'6.83"N 72ツー47'0.42"E 3.2 DEFINING THE STUDY REGION: The major criterion for defining the study region boundary, are the rivers Vaitarna and Ulhト《. The Arabian sea on its west and ridge of Tungareshwar hills on its west. Shraddha Sawant LA - 9812

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4.0.

About the Study region

4.1. ABOUT THE REGION

The region is a narrow coastal belt of Mumbai Metropolitan region (Land between western Ghats and Arabian sea , part of west coast of India) It is a Khazan land with a unique coastal estuarine ecosystem. It composes of hills, tidal flats, coastal saline floodplains(converted to agriculture, salt pan and aquaculture land over a period of time), sandy shore and low height mangrove forest. 4.2. CLIMATE

The climate of the Vasai Virar Sub-region can be described as hot-humid with moderate seasonal fluctuations of temperature. Due to a long coast-line and high relative humidity the variations are not significant. There are basically three seasons, with a transitional period of about 15 days between each season.

4.2.1. RAINFALL

The annual average rainfall is about 2200 mm. During this season, the mean maximum temperature is about 30 deg. C. and the mean minimum temperature is about 24 deg. C. with relative humidity.

4.2.2. TEMPERATURE

a) Winter: This extends from October to January with the mean maximum temperature of about 28 deg. C. and the mean minimum temperature of about 16 deg. C. with relative humidity of about 77-85%. b) Summer: This extends from February to May with the mean maximum temperature of about 34 deg. C. and the mean minimum temperature of about 26 deg. C. with relative humidity of about 60%. c) Monsoon: This extends from June to September. The south-west monsoon begins in the first week of June. 95% of the annual rainfall is recorded during this period.

Fig.4.1.GRAPH INDICATING DISTRIBUTION OF RAINFALL (Source:www.world66.com/asia/southasia/india/mahar ashtra/thane/lib/climate)

Fig.4.2. GRAPH INDICATING ANNUAL TEMPERATURE (Source:www.world66.com/asia/southasia/india/maha rashtra/thane/lib/climate)

. Shraddha Sawant LA - 9812

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4.0.

About the Study region

4.2.3. HUMIDITY

Owing to the proximity of the sea the district is on the whole very humid nearly all the year round. The humidity ranges from 49% to 85% with the highest humidity in the month of July. 4.2.4. WINDS The wind direction is predominately from, west and southwest for a major period of the year. The mean wind speed is 16.52 km/hr. The maximum speed varies from 15 to 19 km/hr from June to August. However, the velocity gradually increases reaching its peak in the month of July with directions from the southwest and west. 4.3 TIDAL DATA The area has average annual rainfall ranging from 1912 mm in Virar to 2600 mm in Nalasopara. The region experience semi diurnal tide of 2high + 2 low tide of unequal amplitude within 12 hours and 40 minutes per day. Following is the tidal level related chart datum. 4.3.1 WIND DIRECTION General direction of wind from the North to west quarter, with seasonal variations as below

4.3.2 CURRENTS The currents in the harbour are essentially caused by the tides and not influenced to any extent of monsoon. The tidal flow is unsteady and the magnitude and direction varies with respect to the location time and depth

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5.0.

Elevation

Fig.5.1. ELEVATION MAP Source: Global mapper for contour (interval 0.5m ) Demarcation of HTL, LTL for Vasi Virar sub region in CRZ Map

5.2 ELEVATION Due to the constant tidal inundation and down flow of two neighboring rivers the central portion forms a low lying area. This area comes under high tide zone as marked with the red line in the map. The area along the coast of Arabian sea undergoes tidal influences by the wave action. The longitudinal drift of the sea current has resulted in formation of sand barrier and 18 beaches along this coastline by short wind waves.


6.0.

Land- use of the study Region

Fig.6.1. LAND USE PLAN

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6.0.

Land- use of the study Region

6.1 EXTENT OF URBANISATION: Only 22% of the area in Vasai-Virar is urbanized. The remaining 78% of the area still remains free from Urbanization. These occupy the salt pan lands under crz I (around17%), mangrove cover and Reserved forest. 6.2 URBAN CHARACTER The Vasai Virar Region is a narrow coastal belt fringed with dense thickets of cocoanut groves with a near pastoral ambience. Although on Arabian coast this land known as ‘uthalpat’to the locals in richly fertile with fresh, sweet water sources. This area is famous for Bananas & beetle leaves. Strip of land along Arabian Sea coast known as ‘Kharpat’ runs from Chikkal-Dongri in North to Naigaon in the south. Railway line divides this belt which is hardly 3 to 4 Ft. above sea level. Further east is ‘Junglepat’ the rising hills of the Western Ghats with two thirds of the area covered by Forest and once inhabited by tribals.

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7.0.

Chronological evolution of the study Region – Natural history

Fig.7.2. Map of Nirmal - Gaas area from Archaeological Survey of India, Western Circle- Progress report, 1898

Fig.7.1. HISTORY MAP OF ANCIENT SOPARA PORT LOCATION

07th century 7.1.1 Political changes in 7th century Sopara was an ancient port town and the capital of the ancient Aparanta (geographical region of ancient India comprising of the northern Konkan, northern Gujarat, Kathiawar, Kachch and Sindh.) Sopara was internationally famous for its trading port. A fragment of Asoka's eighth edict was found at Sopara, close to one of its landing places, in April, 1882. A Buddhist stupa was discovered at Sopara recently by the Archaeologists. 7.1.2 Physical changes in landscape Ancient trade roads linked Sopara through Kalyan with Nasik, Paithan and Ter in Deccan. Tides pouring in and out from three directions would have been deep enough to permit early shipping of sailing vessels carrying on cargo trade. As the ships became larger, with greater draft. The depth of the creek restricted the movement of ships.Sopara creek became shallow due to silting. The creek near Thane had already silted by then and this resulted to shifting of the port activities to Kalyan. Sopara lost all its importance.

Before the Bolinj and Sopara creek parted completely by drying up in the middle, small vessels were able to reach Sopara by meandering up or down. A canal intended to keep open the communication with the sea when the natural channel began to fail as represented in the ASI map above. 7.2.1 Political changes in 18th century Initially, the Arabs controlled the eastern spice trade into Europe through Persian Gulf. The Europeans were totally dependent on the Arabs for their supplies of products originating from the east. In order to gain the profits by around 1493-94, the Portuguese had explored the entire West coast of Africa and even proceeded beyond the Cape of Good Hope. Therefore, Vasco D Gama was commissioned to find a sea route to India. In 1500, coastal western India was ruled by three regional independent Muslim Sultanats of Gujarat, Ahmednagar and Bijapur, while coastal trade routes were dominated by the Muslim merchants to whom the Portuguese were hostile. At the close of 15th century the Portuguese arrived in India. They started acquiring the areas on the western coast. Subsequently, they occupied Malabar Coast and made Goa the capital city. When the Portuguese turned their attention to Konkan coast, they had to face a strong Muslim resistance. Finally Vasai became a Portuguese enclave and began its journey as the capital of their ‘Provincia do Norte’ A fort was constructed at Bassein in 1535 which was enlarged and strengthened from time to time. 7.2.2 Physical changes in landscape The region has undergone a progressive change in its physical landscape over time. Land carrying Agashi, Nirmal, Sopara and Gas appears to have been an island named Sopara Agar, till almost the 17th century Vaitarana estuary to its north and the Bhui (Bhuigao) tidal inlet to its south. Another island, Vasai Agar seems to have survived till Portuguese times. Surrounding the fort people started settling and the settlement also started expanding spatially. The spatial extent of this Portuguese city during 16th century became quite large for which the need to secure the settlement arose. A wall was built around the settlement, which also acted as the main wall of the fort.

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7.0.

Chronological evolution of the study Region – Natural history 7.3 INFERENCES

SLOW SILTATION OF TIDAL CREEK There was a slow siltation process taking place in the tidal creeks. The dense forest got replaced to small to large agriculture farms. PHYSICAL OUTLOOK TOWARDS LANDSCAPE The Portuguese on understanding the low capability of the muddy areas of tidal creeks introduced bunds, embankments and started agriculture and salt panning. This was done to cater the increasing food requirements with the increasing labourers. On higher elevations the Portuguese preferred cultivation of cash crops like sugarcane, pineapples, cocoa palms and vines (Gazetteer of the Bombay Presidency, 1882)

ECONOMIC ORGANISATION OF SPACE (LAND-USE) A large market was located in front of the Portuguese citadel gate. This market was full of the import commodities from foreign markets as well as fruits, vegetables, grains and various species of fishes brought by the farmers and fishermen of Madrapore. The Portugese came to Vasai purely for commercial purpose, established trade with other countries.

Fig.7.3. HISTORY MAP OF PORTUGUESE FORT LOCATION

18th century

Fig.7.4. HISTORY MAP OF MARATHA TERRITORIAL EXTENT

19th century

CENTRES BASED ON AVAILIABILITY OF RESOUCES They established centres based on availability of natural resources. Lumbering had already set in Tungareshwar during the initial period of agricultural development. Uttan for building stone, Agashi for timber and shipbuilding yard In this way there was an economic organisation of space which helped Portuguese to trade overseas and obtain good foreign exchange.

Fig.7.5. CURRENT LAND USE

mid 20th century

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8.0.

Analyzing natural resources in the study region

Fig.8.1. SOIL MAP Source: The soil map of Maharashtra, Government of India, copyright 1996

8.2 SOILS

Rivers are the main source of sediments which brings large quantity of clay on the upper surface of the land. The huge expanse of mud that got deposited on land near rivers is the product of sand and silt. Due to regular tidal inundation the soil is mostly fine clayey to fine silty and highly moist.

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8.0.

Analyzing natural resources in the study region

Fig.8.2. GEOLOGY AND GEO-MORPHOLOGY MAP Source: District resource map, Thane district, Maharashtra, Government of India c 2001

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8.0.

Analyzing natural resources in the study region

8.1 SOILS 004-Vertisoils, Swelling clayey soil lies in the central depression. The soil swells in presence of water and hence not recommended for construction. 026 -Fine, well drained clayey-skeletal soil on slopes results to excess runoff. 063- Loamy skeletal soil supports good vegetation and allows percolation due to its grain size 021- the excessively drained, fine loamy soil is found on undulating lands and causes severe erosion. The region is covered with alluvium deposits of rivers Ulhas and Vaitarna. Due to regular inundation with tidal water the soil is mostly fine clayey to fine silty and highly moist. The soil is well aerated but, saline. In the elevated areas away from the creeks the soil is loamy and is comparatively less saline 8.2.1 GEOMORPHOLOGY The geomorphology of the region is mainly characterized by highly dissected basaltic plateaus in central depression. Less dissections and structural hills exist over hilly areas. The Deccan traps are found to be well jointed and fractured. These joints are primarily formed during the process of cooling and contracting of the lava flows. These joints or fractures harbour groundwater in deccan traps and permit the water to flow underground from one place to another. Dykes are impervious and act as barriers and stop the passage of water from one side to the other. They act as sub-surface dams. 8.2.2 GEOLOGY The coastal deposits are deposited by sea in form of horizontal overlapping. It consist of is tidal clays of Mendha, sand , beach dune complex rock or Karal and flood loams. These deposits attain a thickness of about 5 m to 10 m and range in age from late Quaternary to Recent. They are mostly confined to area extending unto 6 km inland from present coast. The general stratification of the area is as follows • Habitatational deposits of 1- 3 m in thickness • Karal or beack rock of 1-3 m forming horizontal layers of 3-5 cm thickness and at places interlayed with sand, rich in shells • Greenish grey tidal clay- 2to 4 m in thickness, silty to clayey with shells, shell fragments, wood and animal burrows at places showing mottling

Fig.9.2. GEOLOGICAL SECTION SHOWING COASTAL DEPOSITION OVER CENTURIES Source: Illustration sketched from a report- Sea level fluctuations of North Konkan with the special reference to Soparareport by Savita Ghate, Deccan college, Pune

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9.0.

Instability of Natural resources- Analysis 9.1.1

Ground water Recharge Potential

Fig.9.1. ANALYSIS MAP- GROUND WATER RECHARGE POTENTIAL Source: overlay of soil and geology map , Overlay: Geology map+ Hydrology map+ Elevation map+ Vegetation

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8.0.

Analyzing natural resources in the study region

8.1 GROUND WATER RECHARGE POTENTIAL

9.1.2 INFERENCE

The central depression forms an important recharge area. The excess runoff in the city, based on landuse has reduced this potential for percolation, thereby increasing salinity. The deposition of alluvium by the rivers and tidal deposits near coast forms the primary aquifer in that zone. This aquifer is important recharge zone for protection of well heads.

Shraddha Sawant LA - 9812

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9.0.

Instability of Natural resources- Analysis

9.2.1 CULTURAL PRACTICES OF THE COASTAL VILLAGES

SALINITY AFFECTED AREAS

Fig.9.3. GOOGLE IMAGERY OF COASTAL VILLAGE

Fig.9.4. LAND-USE MAP OF COASTAL VILLAGE

9.2.2 A PORTION OF THE SITE ALONG THE COAST STILL REMAINS A VILLAGE

ELEVATION The old village settlements in the coastal belt are slightly on higher level and moderately plain. The average elevation of the area above sea level is 1.5 to 2 m. CONNCETIVITY TO THE CITY All the coastal villages are connected by the parallel road to the coast- Vasai-Agashi road. The settlements in the form of small ‘gaothans’ are oldest development in the Sub-Region.

POPULATION Population in coastal belt is mainly engaged in agriculture, horticulture and fishing activities. The rural area is 339.10 sq.km. and 2001 population density was 6 persons per hectare but the 11 villages lying along the coastal belt have density of more than 20 ppha. This coastal belt has a population of 77,739 persons as per 2001 census. 9.3. THE COASTAL VILLAGE IS AFFECTED BY

1) Salinity ingression from sea side 2) Salinity ingression from salt affected areas degrading the primary aquifer 3) Urbanisation pressure in future


9.0.

Instability of Natural resources- Analysis

9.3. 1 SALINITY INGRESS

In Vasai Virar, the salt water from tidal inlets have ruined the water of the wells. Against the recharge of 720 ha-,m of rainwater , the withdrawal in the period of 1991-92 was 765 ha-m and the well density increased to 34 wells/ km square to 45 in period 1996-97. Today the entire narrow coastal plain is affected by salt water incursion. Source: ground water contamination due to presence of salt panning in Vasai –Palghar coastal belt. North Mumbai, India- D. Chandrashekharam, Lekha Siraz and S.D. Shah, Department of Earth science, IIT Bombay, India.

9.3. 2TRADITIONAL SHALLOW WATER WELLS ‘BHOWKALS’

Fig.9.5. GEOLOGICAL SECTION OF AQUIFERS

Heavy pumping out of groundwater (withdrawal) creates cone of depression in the water table around the wells. As a result, shallow wells become dry and loose their discharge.

The villages in this belt have good agricultural, horticultural and fishing base and therefore, they are distinct from the villages in the eastern part of railway line situated along and near the National Highway Although on Arabian coast this land known as ‘uthalpat’to the locals in richly fertile with fresh, sweet water sources Traditionally, the Bhowkals are owned and maintained by the community. The women of the community to be specific. Each Bhowkal provides water for about 20 acres and sometimes up to 40 families. Protecting the Bhowkals are trees that act as a fence and with roots that binds the soil. Silt tends to deposit during the monsoons and has to be removed during the dry months. The shallow wells are threatened from two sides, the pressure of the urban lifestyle and the sea.

Fig.9.6. SCHEMATIC SECTION OF CONE OF DEPRESSION

9.3. 3 TUBE WELLS -REDUCING THE FUNCTIONING OF TRADITIONAL WELLS

To add to this, the area close to the coast faces incursion of salt water from the sea. Saline water seeps in to the fill in the empty spaces in the depleted aquifer. The incursion of salt water from salt affected areas also takes place 9.4 CONCLUSION

The dependency on bore wells should be completely banned in the villages due to salinity ingress and dependency the traditional well should be increased. This will recharge primary aquifer of the region. 1. Desiltation of shallow wells needs to be after every rains. This will reduce salinity ingress from sea side and increase the recharge of ground water. 2. The coastal village population of a region engaged in historically-evolved subsistence activities for e.g. fishermen, salt-pan workers, and farmers. The landscape is managed by the villages within the constraints of natural resources. The economic activities are ‘region-specific’ and cannot be shifted and go well along with the setting of the coastal landscape. In the Urbanisation process, the traditional subsistence ‘economic systems ’ of these indigenous communities might prove to be unfit in future. But considering the fact that these villages provide a valuable food resource to neighbouring cities within MMR, they need to be restricted from Urbanisation. 3. Hence the village should be declared as a ‘Well head protection zone and continue restoring its cultural practices.


10.0.

Issues of the region

10.1.0 TIDAL CREEK- AN ESTUARINE ECOSYSTEM

The mouth of the estuary became shallower due to siltation caused by deforestation. The formation of mudflat areas resulted to colonisation of mangroves species around it. The blocked tidal flow due to railway embankment has disturbed the sediment balance in the estuary indirectly. The imbalance of fresh water is due to excess runoff in the area. The fresh water from streams flowing into the estuary is either blocked or is let out to the sea even before it percolates in the ground or mixes with the saline water.

Fig.10.1. 7th century Representative sketch showing dense forest around the tidal creek

Fig.10.2. 16th century Representative sketch Showing forest conversion to agriculture and slow process of siltation

Fig.10.3. 19th century Representative sketch showing mudflat reclaimed to salt pan and blocking of tidal flow in the estuary causing water imbalance

Fig.10.4. 21st century Representative sketch showing choking of tidal water leading to waterlogging in the city.

10.1.1 IMBALANCE IN WATER ENTERING THE TIDAL CREEK INLET FROM SEA

The water balance controls the sediment balance in the estuary. The water is the only medium through which the sediments are circulated which otherwise will only settle at a location. In this case, the blocking tidal flow due to railway embankment has disturbed the sediment balance in the estuary indirectly.

Fig.10.5. Section showing process of churning of sediments during flood tide and slow deposition during ebb tide

10.1.2 IMBALANCE IN FRESH WATER ENTERING THE TIDAL CREEK DUE TO RUNOFF

The imbalance of fresh water is due to excess runoff in the area. The fresh water from streams flowing into the estuary is either blocked or is let out to the sea even before it percolates in the ground or mixes with the saline water. 10.2 FURTHER FOCUS AREAS FOR ANALYSIS-

1) Analysis of existing storm water management plan to reduce further runoff from catchment areas directly into the sea. 2) Identifying the reasons for excessive salinity along the tidal creek areas 3) Find an ideal land use for ‘Salt pan’ lands, which are susceptible to reclamation for housing in future .


11.0.

Analysis of the issues 11.2.1 Ecotone 1 Area within close proximity to sea and gets regular inundated with 2 high+2 low tide daily The massive root system of mangroves dissipates wave energy and slows down tidal water enough that its sediment is deposited as the tide comes in, leaving back all except fine particles during ebb. 11.2.2 Ecotone 2 Area getting inundated with spring tide at every fortnight. The vast expanse of salt pan area also allows tidal surge to move inside laterally ,allowing enough churning of sediments v i l l a g e to deposit and leave during ebb. Some of the salt pans are good source of ‘Artemia cyst zooplankton’.

Fig.11.1. ECOTONE MIGRATORY BIRDS

MAP

HABITAT

FOR

11.2.2 Ecotone 3 Circulation of sediments is very low and hence water remains stagnant for very long time. This is due to the roads then encircle the mangroves and block the inter-tidal water entering the area. Areas potential for tidal surge to come in but is blocked after a point by embankments or deposit sediments at a location only.

11.1.0 WHY IS RECLAMATION OF SALT PAN LAND IN FUTURE NOT ADVISABLE

The land which is used by saltpans and the lease is expiring in 2014. It accounts for around 1,500 acres of land (which is roughly 17% of total area in Vasai) 11.1.1 TO PREVENT FLOOD RISK

The relief area against tide is important to stop floods. Also the inefficiently planned storm water outlets results in backflow during low tide 11.1.2 TO REDUCE LOSS OF MIGRATORY BIRD POPULATION

The salt pans and surrounding muddy areas act as breeding grounds, bird sanctuary, habitats for varied marine and riverine organisms. The circulation pattern of sediment , accumulation and transport defines the habitat quality of marine and estuarine species.


11.0.

Analysis of the issues

According to ‘Avian diversity in and around Bassein Fort and Creek, Dist. Thane, Maharashtra’ - a study carried out by Internation Journal of advanced research. A total of 143 Aves species belonging to 45 families (resident and migratory) were recorded during 9 years of study. Red whiskered Bulbul (Pycnonotus jocosus), White Breasted Kingfisher (Halcyon smyrensis), Blue tailed Bee Eater (Merops philippinus), Black kite (Milvus migrans migrans) , Cattle egret (Bubulcus ibis), Common Myna (Acridotheres tristis) as diurnal and Barn owl (Tyto alba) as nocturnal species were most commonly spotted in the study area. A large number of migratory birds were seen to be visiting the study area in winter season between December to February.

The most dominant species of mangrove is Avicennia marina, some other common species were also noted from this area. Mangrove diversity attracts many water birds in this area the most commonly observed birds were Brown headed gull, Gull billed tern Fig.11.5. Graph showing and Cormorants. no.of Winter migratory, Resident, local migratory, Monsoon migratory and Post- monsoon migratory bird population of site as per International Journal of Advance research

A total of 143 bird species was recorded in the study area, of which , 66% were migratory 22% Local migratory, 41% Winter Migratory, 1% Passage Migratory and 2% Monsoon migratory) and 34% were Residing species

Fig.11.6. Photographs of spotted bird species as per the report of international journal of advance research

The diversity in this area is not very much influenced by anthropogenic activities in the surrounding area but the increasing anthropogenic are of great concern considering the future existence of these species. Large number of migratory and residing birds are recorded, indicates a good breeding and feeding conditions in Bassien fort with creek. A large number of winter and local migratory birds also visit this area during winter season (December to February).

Fig.11.7. pie chart showing no of threatened, Critical, vulnerable to extinction and least concerned species near Bassein fort area as per International Journal of Advance research


11.0.

Analysis of the issues

Fig.11.10. PHOTOGRAPHS OF RECLAMATION AND EMBANKMENT ON THE SITE BLOCKING THE TIDAL FLOW

Fig.11.7. WATER MOVEMENT DURING LOW TIDE Source: Google earth imagery for base map, Demarcation of HTL, LTL for Vasi Virar sub region in CRZ Map Fig.11.9. DRAINAGE PHOTOGRAPHS

NETWORK

11.4.1 WATER MOVEMENT DURING LOW TIDE

The storm water network is combined with the sewerage leads to discharge of raw sewage in the nallahs during heavy storms. The network is mostly open and at few places consist of close drains causing unhealthy conditions. All nallahs are provided with gates, which get closed during high tide preventing the sea water from entering the nallahs. As the tide recedes the gates get opened releasing water to the creek. Back water during high tide keeps nallahs full and the water from city does not flow and remain stagnant. 11.4.2 INFERENCE

There is excess pressure on main nallahs running parallel to Western railway line as it is responsible for collecting all the water from the city ,which is, -The fresh water coming down hill forming micro catchments of the creek. -Sewage water that combines it due to no separate sewerage network planned in the city.


11.0.

Analysis of the issues

Fig.11.11. SALINITY AFFECTED AREAS Source: Metadata, Bhuvan.org

INCREASED SALINITY OF WATER TABLE

Water flowing down streams is trapped by the railway embankment.

Waterlogged areas with saline water does not support plant growth

• INADEQUATE TIDAL FLUSHING • WATERLOGGED AREAS

9.1.2 INFERENCE

The central depression forms an important recharge area. The excess runoff in the city, based on landuse has reduced this potential for percolation, thereby increasing salinity.

Elevated land and introduced embankments together block the water leaving it stagnant Fig.11.13. REPRESENTATIVE REASON FOR SALINITY, INADEQUATE TIDAL FLOW.

Water entering inside the site during spring tide remains water logged in salt pan area SKETCHES SHOWING WATERLOGGING AND


11.0.

Analysis of the issues

Fig.11.12. ZONES BASED ON CAUSES OF SALINITY & AREAS FOR SURFACE WATER DETENTION Overlay: Elevation map+ Micro Watershed+ HTL areas The railway embankment cutting through the site blocks the tidal flow at various location is explained in the map THE RAILWAY EMBANKMENT CUTTING THROUGH THE SITE BLOCKS THE TIDAL FLOW AT VARIOUS LOCATION

11.5.1 FRESH AND TIDAL WATER- LOGGED AREAS

The storm water network is combined with the sewerage leads to discharge of raw sewage in the nallahs during heavy storms. The network is mostly open and at few places consist of close drains causing unhealthy conditions. All nallahs are provided with gates, which get closed during high tide preventing the sea water from entering the nallahs. As the tide recedes the gates get opened releasing water to the creek. Back water during high tide keeps nallahs full and the water from city does not flow and remain stagnant. 11.5.2 INADEQUATE TIDAL WATER FLUSHING

The stagnation of tidal water in the mangrove wetland during summer helps maintaining the soil salinity suitable for mangrove growth. Low tidal water inflow in the inner areas of mangroves leads to their stunted growth


12.0.

Land Suitability

Fig.11.14. PROPOSED DIVERSION TO REDUCE WATERLOGGING IN LOW LYING AREAS

11.6 ZONES OF TIDAL FLUSHING

As per the frequency and height of tidal flushing each zone receives, zones areANALYSIS

INADEQUATER STORM WATER NETWORK

ISSUE PRESSURE ON EXISTING DRAINAGE NETWORK COMBINED DRAIN FOR SEWAGE & STORM WATER

WILL REDUCE WATERLOGGING IN THE CITY

PROPOSED DIVERSION OF DRAIN

SUB TIDAL ZONE -Area under water most of the time. They cover portion of mudflats mostly exposed during extremely low tides INTERTIDAL ZONE -Area exposed to air at low tides and is underwater at high tides. This zone is flooded by tides a day. HIGH TIDAL ZONE -Area which gets flooded by spring tides ELEVATE LANDS -Uplands which remain unaffected by tides


12.0.

Land Suitability

Fig.11.14. PROPOSED DIVERSION TO REDUCE WATERLOGGING IN LOW LYING AREAS

Proposed diversion drain to reduce the pressure on existing nallah

11.7 LAND SUITABILITY ZONES

ANALYSIS

INCREASED SALINITY OF WATER TABLE

REASON

INADEQUATE TIDAL FLUSHING

BRAKISH WATER ZONE

WATERLOGGED AREAS OF SALT PANS

FRESH WATER ZONE

BRAKISH WATER ZONE Brakish to saline water zone, suitable for natural colonisation of mangroves. By creating an embankment and removing the salt pan bunds that exist currently, mangrove canal plantation could be done. FRESH WATER ZONE Area to be restored as fresh water by stopping tidal flow, to reduce ground water salinity. By adding a flood gate to stop the tidal surge beyond a limitation could help converting the central portion of site to fresh water zone. This central area needs to get waterlogged with fresh water for 2 monsoon period. The salt and saline water is flushed out from this central portion as marked with arrow in the map.


12.0.

Land Suitability- Processes

12.1.1 PROCESS OF LEACHING OUT SALTS FROM SALINITY AFFECTED AREA

There is a presence of saline soil with efflorescence paths at surface of land (as per Bhuvan.org) The area consist of saline soil with high concentration of soluble salt up to great depth. A thick layer of salt is first needs to be scrapped off. The area needs to remain water logged for 2 monsoon seasons into to wash away the excess salts. Source: Bio drainage-Eco-friendly technique for combating waterlogging & salinity, Central soil salinity Research Institute, Karnal (India) 12.1.2 DRAINAGE MEASURE TO WATERLOGGED AREA

Drainage is an effective measure to solve the problems of waterlogging and soil salinity leading to increase in the yield. By installing the Sub surface field drains, the water stagnation is completely removed. The average water table depth is lowered after the drainage. 12.1.3 EXCAVATING SUB SURFACE DRAINS

A section of drain should be excavated at 50 m spacing to a depth of 1.0 to 1.1 m with 1:1 side slope, 0.5 m bottom width and 0.1 - 0.2 per cent bed slope in clayey soils The sub surface drain are interconnected to a main deeper drain. This main deeper drain is sloped towards the sea. Within two monsoon seasons the salinity of the area could be reduced and becomes suitable for crop cultivation.

Fig.12.1. SCHEMATIC SECTION OF DRAIN FIELDS

Fig.12.2. PROCESS OF LEACHING OUT SALTS FROM SALINITY AFFECTED AREA Source: Landscape Planning- Environmental application , William Marsh


12.0.

Land Suitability- Processes

12.2.1 RUNOFF WATER VOLUME IN CREEK WATERSHEDS

The runoff coefficients with respect to the study region is considered based on following - Barlow’s table (Source: Manual on artificial recharge of ground water, Central Groundwater board) - Slope, Vegetation, Rainfall and Soil type Calculations of total volume of water in the basins of the region and total volume as runoff in the basin.


12.0.

Land Suitability- Processes

Shraddha Sawant LA - 9812

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12.0.

Land Suitability- Processes

Shraddha Sawant LA - 9812

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12.0.

Proposal ANALYSIS

ISSUE

WATER SCARCITY

STORM WATER RUNOFF

WATER BODIES

FRESHWATER RUNOFF TO THE SEA CAN BE REDUCED

Fig.12.3. PROPOSED LOCATION OF WATER BODIES ON SITE


12.0.

Proposal

Fig.12.4. PROPOSED PLAN

12.3.1 TIDAL CREEK RESTORATION

Tidal inlet near Vaitarna river -Removal of salt pans near Vaitarna river tidal creek and reduce inadequate flushing of tidal water by inducing mangrove planting or canal planting. Mangrove prologues are planted on slopes of canal. Within 5 years the mangroves wil establish naturally. Tidal inlet near Ulhas river-Allow natural colonisation of mangrove species the fresh water from Tungareshwar forest which is otherwise drained out to sea is allowed to mix with the mangrove mudflat area


13.0.

Proposal

13.1.2 LAND AGRICULTURE

SUITABILITY

FOR

After the salinity is reduced the land is suitable for agricultural produce. Alluvium deposits 5-10m deep present here are loose, unconsolidated deposits of soil or sediments, which has been eroded by water in some form. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel Because of this combination of silt , sand, clay and organic matter they are good for crops.

Shraddha Sawant LA - 9812

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14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

Thames Estuary, UK: 2003-ongoing The Parklands vision is to regenerate and develop urban and rural open spaces which are connected together to create AN ACCESIBLE AND COHERENT LANDSCAPE. This will improve the quality of life for people who live in the Thames Gateway, and the experience for those who visit and work in it. Parklands spaces should be sustainable and contribute towards the development of the Gateway as an eco-region.

THE NATURAL Over 40 per cent of the Thames Gateway area were classed as ‘wilderness’ including the rivers. And is therefore designated as places of nature conservation importance. The large tidal range gives the Estuary an ever changing character. There were extensive wetlands including freshwater grazing marshes, intertidal salt marshes and mudflats

THE MANAGED Many of these special landscapes have been actively changed and managed by people for centuries, a process that continues today. It is an intricate place of dykes, creeks, inlets, bays, mud flats, sand flats, canals, ditches and islands. There are modern and ancient flood defences and drainage systems throughout the area

THE MODIFIED A certain portion of landscape has been shaped by millennia of human activity and its traces are evident from pre and post industrial activities. Marshes and swamps have been transformed for over 2000 years to become a human landscape containing half a million homes, 11 major port clusters, freight yards, power stations, and large industrial complexes


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

The Thames Gateway has seen major land reclamation. More than 40 per cent of the land has been reclaimed from the Estuary starting at least as far back as the Roman era. There continue to be strong visual links between working and living landscapes, which is an important part of the area’s visual identity. The project sets an example of UK’s first ‘eco-region’ in the Thames Gateway and support improvements to the environment.

The vision: This coherent landscape has shaped a ‘constellation of places’ and in many

these origins are powerfully expressed by the remnants of built heritage from this maritime past. Creating an exceptional Parklands landscape is critical in transforming negative perceptions of the Thames Estuary as a place. The vision can be implemented over time by a variety of organisations at national, regional and local level.


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

It will be seen as not only an economic hub, but also a landscaped area of quality, just as the Thames Valley is today. It should become a place for tourism and recreation, where people from the UK and internationally visit to experience a landscape that’s as good as a national park. By 2040-2050, the project envisages, 10,000 hectares of new forest and woodland as well as new marshes and wetlands; we can easily imagine up to twenty new National Nature Reserves, and local food and materials produced in the estuary on a large scale. In urban landscapes of Thames estuary Parklands, there is an evaluation that no resident lives more than 300 metres from a high quality local park. A complete Thames Estuary Path, restoration of piers and promenades and new walkways and nature trails. The world’s largest wetland estuary. FACTORS CONSIDERED GREEN -BLUE-BROWN CONNECTIONS LANDSCAPE AS THE FIRST INFRASTRUCTURE In 2009, Sir Terry (Farrell Architects) was appointed by the Homes and Communities Agency to refresh the Thames Gateway Vision for the 21st Century. His concept for the Parklands Vision was based on landscape and environmental improvement as the first step in - Attracting investment and -Improving the quality of life for its one and a half million residents. THE PERCEPTION OF PLACE Thames Gateway is regarded as a place of relatively cheap land and housing. Similarly, the region is acknowledged for its close proximity to core city of London. The project identifies the ‘Parklands’ potential in transforming negative perceptions of the Thames estuarine landscape.

PART OF EVERLY DAY LIFE The project envisions to create an of integration of Water, urban and green. A continuous Parklands landscape that reaches into each Thames Gateway community making green and open spaces part of people’s everyday lives. ACKNOWLEDGING THE REGIONAL ECONOMY The Parklands vision acknowledges the Estuary’s industrial and functional past, and its strategic importance as the room of the regional economy, to grow now and in the future.


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary THE URBAN -GREEN Greening the existing urban landscape to create cultural and social interactions.

THE LINEAR CONNECTING PARKLANDS Connecting the green with existing forest and linking them with the major transport corridors. THE COMMUNITY PARKLANDS Linking the community parks to the river and enhancing each park with individual identity an character. Improving the access to each of the park A combination of urban areas, heritage structure, port lands, Agriculture, parks, urban squares & waterfronts

INFERENCES -Landscape as the first infrastructure - The environmental improvement should become the first step to attracting investment and improving the quality of life of people instead of other infrastructures like roads, tracks, etc. -The case study becomes the basis of deciding the ratio of built and unbuilt areas surrounding the ecologically sensitive areas of the a tidal creek. -The project identifies the ‘Parklands’ potential in transforming negative perceptions of the Thames estuarine landscape. The mudflat land or a salt pan land for that matter is seen as a wasteland and hence this perception needs to be changed.


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

PROJECT DETAILS Estuary Edges: Ecological Design Guidance, which shows you how you can make a positive contribution to one of our most important environmental and social assets, our estuaries. Well-planned developments next to the estuaries can create better places to live and work. When reconstructing or refurbishing the banks of an estuary, the project included features that support wildlife, improve public access, and educate people about the importance of protecting the environment. • The natural edge restoration The natural habitats of the estuaries are often missing, especially in urban areas. For example, in the Thames Estuary only around 2% of the tidal banks are now natural in profile. There are three estuary edges:

different

categories

for

designing

1 . B i o e n g i n e e r e d d e s i g n s – These designs rely entirely on plants for longterm protection from erosion. Bioengineering techniques can be appropriate in any situation as they m i m i c n a t u r a l s y s t e m s . However, the natural estuary state may have been changed by man to such an extent that bioengineering may be inappropriate. 2 . B i o t e c h n i c a l l y e n g i n e e r e d d e s i g n s – the engineering provides the structure and any ecological elements are simply added on. These designs include structurally engineered elements that form t e r r a c e s t o h o l d s i l t s a n d s o i l s . The ecological value of such designs varies widely, but can be high. 3 . H a r d e n g i n e e r i n g – these designs are used when there is too much water energy for anything to attach, other than seaweed and very exposure-tolerant invertebrates. T h e e c o l o g i c a l v a l u e o f s u c h d e s i g n s i s generally negligible. • Then a local trial sites suitability of a design.

are

created

to

test

Source : http://openbuildings.com/buildings/thames-estuary-parklands-masterplan-profile-5716/buildings_data http://www.thamesweb.com/projects-introduction/estuary-edges http://www.terryfarrell.co.uk/projects/estuary-parklands/

the


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

PROJECT DETAILS 1 . B i o e n g i n e e r e d d e s i g n s – In bioengineered designs, plants are essential for the long-term integrity of the water’s edge. Certain hard elements included are less • Where an a n c h o r e d b i o d e g r a d a b l e c o i r (coconut fibre) erosion control blanket was used, was planted with pre-grown estuary grown Common Reed. This technique may also be appropriate on infrequently inundated upper slopes where there is a risk of erosion eddies • The main aim here may be to ensure that the river edge achieves n e t b a l a n c e b e t w e e n a c c r e t i o n a n d e r o s i o n , by initially favouring the deposition of sediment. This ‘brushpacking’ technique promotes r a p i d s e d i m e n t a t i o n . Results Plentiful supply of f i n e s e d i m e n t a n d n e t a c c r e t i o n / e r o s i o n balance achieved at lower tidal levels. S t a b l e v e g e t a t i o n e s t a b l i s h m e n t anticipated in the long term, the lowest fringe being colonised by Sea Club-rush species( in case of Thames estuary).


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

PROJECT DETAILS • In the first 12 months no erosion occurred on the slope and the coir matting and brushwood fascines had not been damaged. • Cell-grown Common Reed planted on the lower slope largely unsuccessful but subsequently started to colonise naturally. • Grassland vegetation establishment from seeding the upper slopes successful despite limited sedimentation. • Considered very successful in ecological, social and economic terms.

SUITABLE SITES FOR APPLICATION Bioengineering is generally only selected when the erosion-protected estuary edge is 'inherently stable'. Most examples of bioengineered tidal solutions are in brackish water. Tidal level below Mean High Water Neap tide level Generally 'low‘ to 'medium' loadings (pedestrian to vehicle)


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

PROJECT DETAILS 1 . B i o t e c h n i c a l l y e n g i n e e r e d d e s i g n s – In bio technically engineered designs, plant material alone is not predicted to withstand the peak forces for the anticipated severe event. So the planting needs to b e r e i n f o r c e d w i t h structurally engineered components. • In this case g a b i o n m a t t r e s s e s were lined with soil fines infill to the stone first and then a thick coir loop mat was laid under the lid of the basket to prevent wash out of content. The importance of careful installation of substrates and matting and the contribution of the vegetation to the integrity of a steel gabion are illustrated by this example of bioengineering Results The strong erosion forces and durations gave cause for the designers to be concerned that brushwood revetments should be both layered (brushwood fascine layering) and t h e n r e t a i n e d w i t h a w i r e ‘rocknet’. In this situation, if the sediment is not deposited as expected, then the b r u s h w o o d c a n b e e x p o s e d t o t h e a i r a n d r a p i d l y d e c a y , exposing the mesh and potentially creating a hazard. SUITABLE SITES FOR APPLICATION Gravels/ sands in a Synthetic Soil Cell plus appropriate plant regime Rock rolls and Turf

Reinforcement Mats Definitely viable at brackish Salinities and probably at Seawater salinities Generally 'medium‘ to 'low‘ loadings (pedestrian to vehicle).


14.0.

CASE STUDY – T h a m e s

gateway parkland estuary

PROJECT DETAILS 1 . S t r u c t u r a l l y e n g i n e e r e d d e s i g n s – Where there is not room for a more gentle slope, so a steep or near-vertical solution is required, habitat can still be created by establishing plant communities on steps, terraces or ‘ledges’ on hard engineered walls • The design of terraces will differ depending on their location or position within an estuary. The aim is to promote successful establishment of vegetation through providing a revetment that will trap and hold silt and water at the optimum tidal levels for plant growth, but not become waterlogged. • Wherever possible the aim should be to install at least 1m depth of gravel and growing medium, generally above a geotextile liner. Results Limited scope for human access, which might be addressed in future schemes by a variety of slipways or floating pontoons (where ecological and safety constraints permit).

SUITABLE SITES FOR APPLICATION Gravels/ sands in a Synthetic Soil Cell plus

appropriate plant regime Rockrolls and Turf Reinforcement Mats Definitely viable at brackish Salinities and probably at Seawater salinities Generally 'medium‘ to 'low‘ loadings (pedestrian to vehicle).


Conclusion Most of the natural landscapes in today’s date have been modified by human activities. Hence, they are embedded with several meanings and values which people assign to them. Landscape, as a term, has gained several meanings in wide range of disciplines. Mainly it is associated with the physical features of an environment; it also refers to cultural changes through time. And these cultural changes are product of people’s engagement with the landscape and the values that they associate to the same. The region used to be a village and started gaining popularity for its scenic value due to proximity of Town centre, attracting a large population. In today’s context The area of study –Vasai-Virar today lies around the busiest, globally developing city of Mumbai(Bombay) and supports enormous floating and standing population. The landscape values have changed. The tidal creek was previously looked as a source of livelihood. The region has undergone several land- use alterations to reclamation. The tidal creek was divided into several bunds and got transformed into a saltpan . With the increase in housing development around the suburbs, the tidal creek is going through further degradation from salt panning to reclamation. This has drastically altered the ecological functioning of the creek, that once existed. Further degradation would not only affect the tidal ecosystem but also cause flooding due to choking of drains. Inference : Firstly, the salt panning activity does not gain economic benefits in today’s scenario. The salt pan lease have got over and Government plans to propose a new land use for the region. However, because of high salinity of the soil and the flooding risk it will face, the land cannot be directly redeveloped

Hence, the proposal states that the carrying capacity of the region has already exceeded and further reclamation of the tidal creek is not an advisable option. Also the proposal states to remove several salt pan bunds and normalise the tidal inundation in the area. This will result in natural regeneration of mangrove forest. As per the proposal, there would be an increase in people’s dependency on agriculture which will support the socio economic group. The natural colonisation of mangroves would safeguard the city from prospective flooding and bring back the lost habitat for birds. Conclusion : The entire coastal belt near globally developing city of Mumbai is getting extensively transformed. The land use pattern is going through major alterations from agriculture, salt panning, fisheries to reclamation and housing. There has been an economic shift from region- specific economy to market driven economies. With the increasing water supply demand the salinity of existing ground water needs to be tackled is highlighted in the proposal. Also the cultural practices of the people living near the tidal creek areas and their subsistence economy is largely dependent on the estuary and cannot be neglected in future.

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Bibliography and List of resources List of Documents and Maps 1. Coastal wetland map, Maharashtra, Space Application Centre(ISRO)- Plate 6.8 2. Development Control regulations 2001 for Vasai – Virar sub region (sanctioned) Act, 1996. 3. Cultural landscape values of Rural Landscape- Perception of Outsiders and Tourists, Kamarul Bahrain Shui, Faculty of Architecture, Planning, Malaysia - Academia.edu 4. Bio drainage- Eco-friendly technique for combating Waterlogging & Salinity- Central soil salinity research institute, Karnal (India) & Haryana forest department, Panchkula (India) 5. Between the city and the salty sea - The wells of Bhuigaon, Thane, Greater Mumbai Guest post by MS Gopal- India Water Portal. 6. Coastal regulation zone- An India approach for Coastal Management by K.V.Thomas, Scientist G & Head, Marine Sciences Division, Centre for Earth Science Studies, Thiruvananthapuram, India. 7. Coastal Land-use Change by Reclamation of Tidal Flats along the Western Coast of the Capital Region in Korea by Manik Hwang, Seoul National University, Seoul, Korea. 8. Sea Level fluctuations of North Konkan with special reference to Sopara by Savita Ghate, Department of Archaeology, Deccan College, Pune, India- Current Science, Dec 20,1988, Vol 57, No. 24 List of Books • Dredge, Drain , Reclaim, the art of a nation by Dr.Johan Van Veen. • Mc Harg, IanL, 1956, Design with Nature, John Wiley and Sons, NY 1967 • Changing land use patterns in the coastal zone : managing environmental quality in rapidly developing regions by Kleppel, G. S. & others Eds. • Introduction to coastal geomorphology by Pethick, John. • Estuarine ecosystem by Mclusky, Donald S. List of Referred unpublished thesis • The impacts of Land Reclamation on Fisheries resource of Ashtamudi wetland, Kerala by Minu Ramachandran (EP0805), Faculty of Planning and Public Policy, Cept University, 2006-07 • Thesis- Conservation of Mangrove ecosystem in Urban areas, Case-Manori creeek, Mumbai by Rutuja Ranade (LA9308) Newspaper Articles Concrete jungle threatens Vasai

By Nauzer Bharucha, TNN Oct 4, 2003, 01.16am IST

Vasai villages battle to keep sea away from their door By Anil Singh, TNN Jul 16, 2003, 11.43pm IST

Where have the farms in Vasai gone?

By Priyanko Sarkar, TNN Nov 24, 2008, 03.03am IST

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Shraddha Sawant_CEPT university: Landscape Architecture thesis  
Shraddha Sawant_CEPT university: Landscape Architecture thesis  
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