1. 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

2. 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)

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

4. 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

6. 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

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

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

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

13. 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

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

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

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

26. 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

30. Converted area within 100 m of streams = 10.86 ha

31. `

32. Converted area within 100 m of canals = 18.38 ha

33. 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

34. 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

35. 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)

36. 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…

37. 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

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

39. Thank you