Impact of Urban Sprawl on Land Use in the Kol Wetlands of Thrissur District, Kerala KISHORE A VIMOD KK SALIM ALI FOUNDATION KERALA FOREST RESEARC INSITUTE

Importance of Kol Wetland Rich in Biodiversity - especially winter site for migratory birds (Jayson E.A. 2002) High Agricultural productivity compared to other paddy fields (Srinivasan J. 2011) Part of Vembanad-Kol Ramsar Site (Ramsar Site Information Sheet)

Threats Urban sprawl, high real estate prices (Nikhil Raj, Azeez 2009) Intensive chemical use in agriculture (Srinivasan J. 2011)

Study Area 2 km radius area with the gated colony ‘Sobha City’ as focus Junction of two canals Large area reclaimed flouting norms Other conversions in the vicinity in last 10 years

Objectives To Find out the area of paddy field and water bodies lost to conversion from 2005 to 2015 To identify the portions of streams and canals vulnerable to blockages in future Identify the threat to biodiversity due to paddy conversion

Dataset LANDSAT imagery from 1997, 2001, 2015 Footprints of buildings, roads and canals in study area from OSM Cartosat1 DEM

Software Tools Used QGIS: vector operations ILWIS: image classification SAGA: stream network Open Street Map

Classification of Landsat imagery Built up Paddy Bare Soil Homestead/Mixed Crop Water body

Classificaton: Challenges and Inferences Variety of signatures for different parts of paddy field even during dry season; helpful only in making qualitative conclusions, and not area analysis Area of gated colony clearly appears as ‘Bare Soil’ in both the 2001 and 1997 images, so conversion possibly happened before that

Visual Interpretation Alternative classification done by visual interpretation Classes: Paddy/Wetland and Homestead/Converted

Gated colony area shown as ‘Agriculture, crop land’ in Bhuvan LULC 2005-06 ‘Built up, urban’ in Bhuvan LULC 2011-12 Our analysis of Landsat imagery suggests that the area was converted prior to 1997.

Stream Network Analysis Stream Network from Cartosat Canals from OSM Identify converted areas within 100m of stream network and canals

Study with high-resolution imagery Footprints of several buildings on converted land in study area available from OSM Digitized the remaining ones (using Google Satellite base layer in QGIS) Limitation: No historical comparison possible Only obvious conversions included

Converted area within 100 m of streams = 10.86 ha

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Converted area within 100 m of canals = 18.38 ha

Conclusions… Comparison of Landsat imagery gave a qualitative impression of Land Use change, but too crude for area comparison Conversions clustered on flanks of major roads

Conclusions High stream density, presence of fourth order stream: vulnerable to water logging in case of blockages Significant conversions within 100 m of stream network and canals

Further Studies and Action... Possibilities for Further Studies and Action... Paddy field/Wetland Information System for entire Kerala: Demarcate approximate boundaries of paddy fields and wetlands in vector format (with the help of Bhuvan/improved image processing methods)

Further Studies and Action… Possibilities for Further Studies and Action… Create portal to collect volunteered geospatial information Contact details of local farmer groups Boundaries of ‘Padashekharams’ (Paddy clusters) Organic farms, heirloom seeds etc. Converted areas and so on…

Further Studies and Action… Possibilities for Further Studies and Action… Analysis to identify areas vulnerable to conversion Paddy/wetland close to major roads Paddy/wetland close to major towns/cities Stream/Canal network analysis Identify converted areas near streams and canals

References Jayson E. A. 2002. Ecology of wetland birds in the Kole lands of Kerala. Kerala Forest Research Institute, Peechi. Jeena T. Srinivasan 2011. Agricuture – wetland interactions: A case study of the Kole land Kerala. Centre for Economic and Social Studies Begumpet Hyderabad. Ramsar Site Information Sheet no. 1214. https://rsis.ramsar.org/RISapp/files/RISrep/IN1214RIS.pdf. (Accessed 18 December 2015) P. P. Nikhil Raj, P. A. Azeez 2009. Real estate and agricultural wetlands in Kerala. Economic and Political Weekly 31 January 2009.

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