Vegetation pattern analysis of Karuvannur watershed, Kerala using remote sensing and GIS

Abstract

The Karuvannur River is an important river of Kerala that drains into the Northern part of Vembanad Kole wetland system, a Ramsar site. Urbanisation, changes in land-use practices and unscientific sand mining have resulted in the deterioration of water quality and also increases the water shortage especially during extreme summer season. Deforestation, for food fodder and fuel wood, and indiscriminate sand mining in the catchments area have resulted the drop of water table level of the area. Unscientific land-use and cropping pattern changes in a watershed, often cause problems in water conservation, both in upland and down streams. In a watershed both uplands and down streams are closely interlinked. The nature and extent of their linkage specially in a forested ecosystem needs more attention. The Karuvnnur watershed has a total extend of 956.95 km2 and drainage density was estimated as 1.104. In the present study efforts have been made to use Remote Sensing data and GIS Techniques for mapping and monitoring of the vegetation pattern of the watershed area. It is found that 36.48% of watershed area is covered by forests, plantation (Rubber and Teak) occupies 5.49% of the area, and 1.35% of the area by scrublands. Reservoir and other water bodies occupy 9.08% of the watershed area.