Significance of Micro-morphology in Town Planning

Significance of Micro-morphology in Town Planning –A Case Study of Kolkata New Town

SK AKHER SENIOR RESEARCH FELLOW, LADY BRABOURNE COLLEGE, KOLKATA SUBHRA CHATTOPADHYAY ASSOCIATE PROFESSOR, LADY BRABOURNE COLLEGE, KOLKATA

[email protected], [email protected], Abstract: Urban planning often ignores micro-morphological set up of the concerned area. Later on, several environmental problems may originate due to absence of alertness about morphological condition. Nothing is exception for Kolkata New Town planning. Kolkata New Town is a planned township in the east of Kolkata. The town has emerged over 20.3 sq. km of wetland and 40.8 sq. km of agricultural land. This study aims to understand how far the micro morphological set up of the area has been concerned in Kolkata New Town Planning. For this purpose, flow accumulation map has been prepared by ArcSWAT with the help of DEM. It shows that the channel network of the area once converged in present day new town area and then flowed east and then south-east. Later on Kolkata New Town has been developed by filling up the wetland as well as by obscuring the natural flow. In this condition, waterlogging in the town and its peripheral areas is inevitable in coming future. Key Words: flow accumulation, Kolkata new town, micro-morphology, wetland Introduction: In the context of ‘crowding, congestion and sequel’ in Kolkata metropolis,

Department of

Housing, Govt. of West Bengal constituted a Technical Committee in May 1993 for preparation of a preliminary report of the New Town planning accordingly. In 1994 CMDA prepared a concept Plan for development of Kolkata New Town at the East of Kolkata Metro city and adjacent to the East Calcutta Wetland. The master plan was made by Indian Institute of Technology in 1996. In 1999 the Master Land use Plan and detail Sector Plan for township was prepared and West Bengal Housing Infrastructure Development Corporation Limited (WB-HIDCO) formed as plan implementing body. Initially 3075 hectares of land has been acquired by the Department of Land and Land Reform (North and South 24 Parganas, West Bengal of which 68% was agricultural land. The area which has been chosen for development of

Kolkata New Town is confined in between East Kolkata Wet Land in South-West and the Bidyadhari River in the east and hence is morphologically sensitive to natural flowage of the region. Aim: Aim of the study is to examine the locational justification of Kolkata Newtown micro-slop and flow accumulation analysis. under concerned in Kolkata New Town planning.

Objectives: Major objectives are i)

identifying location of Kolkata New Town within the Bidyadhari River basin area ,

ii)

to determine pre-township slope and surface run off through generation of flow accumulation channel within the basin, and

iii)

to reconstruct

drainage channels- their direction and outfalls of the region virtually for

understanding of locational justification of the township.

Location of Kolkata New Town: Kolkata New Town is located between 88.43E to 88.60E and 22.64N to 22.50N. Location of the town within Bidyadhari Basin area is mapped (Fig- 2) by superimposing the base map of New Town (HIDCO) on satellite image (Landsat 8, OLI). Dum Dum, Saltlake City of Kolkata and East Kolkata Wetland are in the west of the Kolkata New Town. Bhangar, Polerhat municipalities of Bhangar Block of Soouth 24 Pargaganas District are located in the east and Nowi River marks the north-east boundary of the town (Fig-1). The town is located within the Bidyadhari Basin area. Its position within the basin area is shown in fig 2. . Altogether twenty four moujas from two blocks (Rajarhat of North 24 Parganas and Bhangar-II of South 24 Parganas of west Bengal) were included for this project. The project area covers 6035 hectors area of land in 2015. The new city is a planned project of the Govt. of West Bengal. The New Town Development Act came into effect in 2007.

Area under wetland: Besides, the area under present New Kolkata once contained a huge amount of water bodies. Consulting topographical maps 79B/6 and 79B/10 through digitization, past wetland units have been identified. The wetland area is calculated from the Topographic Map (Georeferencing, digitizing and calculating the area by ArcGIS) Estimated area under different units are given in Table -1 Table -1 Area under Water Bodies

wetlands Natural Water Body Swamp

Area in sq. km

8.1 12.2

This much area was capable of reserving excess run off during monsoon season. Pre-township slope and surface run off pattern: To understand the pre-township slope and surface run off of the area, the SWAT analysis is done in ArcGIS (Automated method). The SRTM DEM is used as the source of the height information. It is found that slope of Kolkata as well as new town is towards east and south-east. Flow Accumulation of Bidyadhari Basin Area: The flow accumulation map (fig-2) as prepared on the basis of gradient analysis shows that all the water of northern and western part of the river basin accumulate in the Kolkata New Town Area. (Fig-3) Gradient of the area falls from north-west toward south-west. Therefore, in past, flow accumulation channel network as generated within Kolkata and North 24 Parganas converged in the present new town area (fig-3) and again drained out further eastward and southward through Bagura Bil, Nangla Bil and ultimately fell into Haroagong-Kultigong River. Hence the morphology of the area played a significant role in drainage of the region. Now the slope is being changed through erection of buildings and other urban activities. Therefore, this mentioned wetland has been filled up. Hence it can be inferred that the emerging township is now blocking the natural run off of this area. This is one of the causes of water logging problem of Kolkata and surrounding area

3. Concusion: City planning is often done in normative fashion with minimum concerns of local environmental issues. The Kolkata New Town is a well-planned township. The sectoral plan as Central Business District, industrial area, residential area, road network and other aspects have been well comprehended for the Master Planning. But it is evident from this study that the plan is mindless about micro morphometry of the area. As a result, this emerging township is impeding the natural flowage of the area and is exaggerating waterlogging problem of surrounding region.

Fig - 3

Fig - 3

References 1. Bandopadhyay, Sunando el. Al, 2014, River Systems and Water Resources of West Bengal: A Review, Geological Society Of India Special Publication, p – 14.

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