PowerPoint Presentation

Wetland spatio-temporal change analysis and ecosystem services in two urbanizing citiesResearch team: Priyanie Amerasinghe, Matthew McCartney, Kiran Apsunde and Kanika MehraBahir Dar, Ethiopia, 23-29 September 2015

Daniel Van RooijenInternational Water Management Institute

ContentsIntroductionMethodsCase study city characteristics

Introduction: Wetlands in India A wealth of ecosystem service benefits Inadequate attention in the national water sector agenda Urbanization, population increase, land-use changes have impacted Emphasis has been on ecologic and limnologic studies Hydrological, landscape and wetland spatio-temporal change analysis studies are sparse

General account of wetlands in India 3

Methods Two cities (2014): Kolkata, West BengalNagpur, Maharashtra Landsat 7 and 8 satellite images 2000 and 2013 (November/December post monsoon/winter)Supervised Image classification and Modified Normal Difference Water Index (MNDWI); TEEBs approach (The Economics of Ecosystems and Biodiversity) to assess ESS A total of 27 ESS were selected, based on observations and surveys. 4 wetlands were investigated to validate the ESS and wetland dependence by poor communities

Methods used. 50 households per wetland were interviewed to understand the wetland dependence and validation process. TEEB = The Economics of Ecosystems and Biodiversity4

KolkataNagpurCity typeMetropolitan CityMetropolitan CityPopulationKMC- 4.49 millionKMDA-14.77 millionNMC- 2.41 millionPopulation density24,000 persons/ sq. km11,000 persons/ sq. kmAreaKMC-185 sq. kmKMDA-1886 sq. kmNMC-217 sq. kmNMA- 3780 sq. kmMain industriesIT industry Mining and agriculture (Orange City of India)Population Growth rate1.73%n.a.ClimateAnnual rainfall:1,582 mmAnnual mean temperature 250 C Annual rainfall: 1,205 mmAnnual temperature 20-330 C

City characteristics

Photo: David Brazier/IWMIPhoto :Tom van Cakenberghe/IWMI

Location of study sites

KolkataArea: 87,500 ha

Nagpur Area: 92,500 ha

Study areas: urban and periurban areas were demarcated for the study (roughly 30 km) but also taking into account the urban sprawl6

CLICK TO EDIT MASTER TITLE STYLEMapping Natural and Built InfrastructureTCWI = Tasselled Cap Wetness IndexMNDWI = Modified Normalized Difference Water IndexNDVI = Normalized difference Vegetation IndexDN = Digital NumberMNDWI was found to be the most suitable index. The water bodies therefore were extracted using MNDWI

Field Validation of mapped features

Post Validation Changes

Final MapsLandsat 7 -2000Landsat 8 - 2013

Satellite images used to spot the wetlands. The size class was defined, based on the resolution. 7

Wetland Selection and Field Surveys (HH & FGDs)

For each of the ES identified, a score of 1 was given and summed-up to give a final score for the wetland.

Kolkata: Over 389 wetlands subjected to a rapid assessment first: 30 urban and 7 periurban wetlands were scored for ES. Nagpur 12 (4 were periurban). Presence was scored as 1, summed to give the final score. 8

November 2000November 2013Land Cover Changes: 2000 and 2013 Kolkata

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Results from Kolkata 1/2 Size class of 0.36 ha and above were mapped (over 3,300 wetlands) Built up areas (6%) and waste/open lands increased (1%)Water bodies (3%), orchards and trees (5%) Agriculture and shrub lands (10%) decreased 4 types of wetlands tanks, aquaculture/paddy rice, riverine marsh/lagoons and treatment units (10,645 ha)Area-wise tanks constituted 12%, only 1.2% (127 ha) were natural. Rest was the EKW (East Kolkata Wetland)

Results from Kolkata 2/2 50% reduction in wetland area over a 12 year period 37 wetlands were scored for ES. 30 in urban and 7 periurbanNumber of reported Ecosystem Services (ES) varied between 4-20 per wetlandHigh number of ES provided by a majority of wetlands (75% fell within 15-17 range)

Loss in wetlands over the period of study 11

Distribution of ES (%)1Bathing and washing2Recreation3Religious activities4Medicinal plants/food5Fishing6Firewood7Construction Material8Agriculture

30 urban wetlands 7 periurban wetlands (we should have scored more periurban wetlands). ES uses in urban and periurban settings is different. Urban - mostly for bathing, recreational activities, religious; periurban medicinal plants, fishing, agriculture etc. 12

Land Cover in Nagpur City

Year 2000Year 2013

LULC Nagpur 200013

Results Nagpur 1/2 Size class of 0.36 ha and above were mapped (182 wetlands) Built-up area (5%) agriculture/shrub land area (3%) increasedMarginal changes in water bodies Forest area (5%) open fallow land (3%) decreased4 types of wetlands: tanks, reservoirs, water logged areas in quarries and treatment plants (844 ha)

12 wetlands studied in detial, of which 4 were periurban 14

Results - Nagpur 2/290% of wetland area were tanks and reservoirs0.4% were classified as natural Loss of natural tanks (70%) was significant (was obscured by water in quarries)ES scores varied from 15-23, and the distribution was very similar that found in Kolkata

Conclusions Wetlands in Kolkata and Nagpur support a rich diversity of ES No other studies available on wetland spatiotemporal changes that can evidence wetland losses Wetland conservation plan is necessary (Wetland conservation policy drafted but not implemented) Engagement of decision makers and users is important to develop policies that are relevant to wetland conservation.

Thank you WLE program for funding Daniel van Rooijen (IWMI - Ethiopia) Anuradha Adikari and Aruna Jyoti (IWMI-Hyderabad) Stakeholders in Kolkata and Nagpur South Asia Forum for Environment, Kolkata Centre for Rural Research and Community Development, Nagpur

For more info contact Dr. Amerasinghe (p.amerasinghe@cigar.org)