“Applying GIS to Urban Issues in Kolkata“

Focus:

Urban water management

WHOSE Water We Are

Suppose to Manage?

My City

Kolkata is now a Megacity

• the greater Kolkata extending over 1851 sq. km. and holding a population of about 15 million. The Kolkata megaity is bisected by Hooghly river over a length of about 80 km

• southern fringe of Kolkata and the bay (Diamond Harbour) is about 30 km. and as such Kolkata always has the risk of storm surge during the monsoon through river Hooghly streched over a period of four months.

• Kolkata has witnessed series of events involving social and economic changes

• The lack of infrastructure and improper drainage managemnet makes the metro city population quite vulnarable for any events related to flood or water level rise

The Study Area :

The study was planned by World Bank to be carried out in Kolkata. Kolkata is selected

• Because of its size (second largest city in India),

• Level of vulnerability (e.g., the slum population is one third of its total population)

and lives and livelihoods at risk. • In addition, ‘integrated coastal zone

management’ and the ‘capacity building for industrial pollution management’ projects.

Part of the assignment Described in this Paper

• Detailed knowledge of past and present

situations • Establish representative baseline scenario • Visual interactive tool i.e., in a GIS platform

with appropriate projection• Prepare a database of topography (DEM), land

use/land cover, soils, population density, map of special economic zones, biodiversity, locations of important historical sites for coastal basin, including urban watershed, at appropriate spatial resolution

• Climate data

• Storm level and storm surge cyclones

• Land subsidence

• Sea Level Rise (SLR) and tidal heights.

• Urban storm flooding

How the Land Use Changed

1. Urban area 26% to 44%,2. Rural Area 21% to 12%,3. Wet land 14% to 5.5%, 4. Vacant land4% to 0.5%.5. Vegetation 0.5% to 2% and 6. Agriculture 25% to 36%( mainly due to acquisition the

adjoing area.

The area of Kolkata Metropolitan increased from 1552 Sq Km to 1722 Sq Km.

Urban Area

Urban Area

Rural AreaRural Area

Vacant Area

Vacant Area

Vegetation

Vegetation

Agricultural Field

Agricultural Field

Predominat Wetlands

(East Kolkata)

Predominat Wetlands

(East Kolkata)

Land Use Pattern Analysis (KMA)Land Use Pattern Analysis (KMA)

Year 1980 – 86 ( 1527 sq.km.) Year 2005 (1722 sq.km.)

Urban AreaUrban Area Rural AreaRural Area WetlandsWetlands VegetationVegetation Agricultural FieldAgricultural Field Vacant LandVacant Land

KalyaniKalyani

BanshberiaBanshberia

UluberiaUluberia

HowrahHowrah

BarasatBarasat

BarrackporeBarrackpore

KolkataKolkata

BaruipurBaruipur

Kal

yani

Kal

yani

Barrackpore

Barrackpore

Baras

at

Baras

at

Kolkat

a

Kolkat

a

Maheshtala

Maheshtala

Baruip

ur

Baruip

ur

KMA ULB Water supply Type

24

262

17

222

0

50

100

150

200

250

300

GW

POPULATION/1000

GW,SW

POPULATION/1000

Ground Water

Surface and Ground Water

Ward Wise Open SpaceKMC

DATA NOT AVAILABLE

Open Space

Looking back…..

• Water extraction in an unplanned manner decreases the water reserve and peizoteric surface delines

• Water extraction in an unplanned manner decreases the water reserve and peizoteric surface delines

Piezometric Depression: KMC area

7m - 10m

Figure 12

HIGHEST RISK AREA

HIGH RISK AREA

MODERATE RISK AREA

KMC RISK WARDS

The supply end ….what we discussed• The source-the quality-the stock-the management and-the

supply

The Other side of water management

The Drainage….it also need to be seen• The type-the outfall-the present status

Name of Catchment BasinArea of Catchment new

(Sq. Km)Total Population

(As per census 2001)

Howrah Drainage Channel 118 1626615

Rajapur Drainage Channel 68.21 327241

Borajala Drainage Channel 55.8 216646

•Dankuni Drainage Channel 210 1239548

Bagher Khal 92.48 401,952

Nawi Khal 114 2304613

Beliaghata Khal and Bangur Cut 220 4223266

•Kaorapukur Khal Charial Khal and Boat Canal

176 2,046,894

•Tolly's Nala 16 583847

•Panchammgram Cannel 46.13 926281

Details of Drainage Basin of Kolkata Metropolitan Area

Details of Drainage Basin of Kolkata Metropolitan Area

LAND FORM MAP OF

KOLKATA METROPOLITAN AREA

Dankuni Drainage channel

Panchannagram Drainage Channel

Tally Nala

Kaorapukur, Charial Khal and Boat Canal

Shrinkage of Drainage basins

Type/Year Habitat Land

Wet land Agriculture Land

1922 30% 17% 53%

2004 70% 10% 12%

Increase in habitat Land more than 100% since 1947

Few Major concerns• High Rise Buildings

and

• Uneven decadal growth rate

MAP SHOWING WARD WISE POPULATIONDECADAL GROWTH RATE OF

KOLKATA MUNICIPAL CORPORATION 1991--2001

DIAMETERDIAMETER

DIAMETERDIAMETER

Settlement in the Basin areas causing hindrance to water flowAbsence of sewage disposal system in the newer settlements caused pollution to streams and rivers.

Ground water can no more be considered as a unlimited water source for domestic use, as over extraction has resulted in deterioration and contamination of aquifer.

HOW ARE WE PLACED NOW

IT is time for all of us

to act together

to make up the loss we made……

It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair . . ."

Charles Dickens (A Tale of Two Cities).