EXTRACTING VEGETATION INFORMATION FROM SATELLITE DATA FOR THE NILWALA CATCHMENT AREA, SOURTHERN SRI LANKA

Abstract

It is evident that increasing human activities on forest resources can lead to floods, soilerision, loss of bio diversity, and increase in atmospheric gases causing global warming,Sustainable management of forest resources requires accurate data on the current status ofthe environment as well as tools to support the decision making process, Remote Sensingand Geographical Information Systems have increasingly been used as decision supporttools, Particulaly, recent advancements in satclitc remote sensing have facilitatedacquiring valuable data and information in assessing the current status of thc environmentat varying levels of detail. Thc purpose of this study is to assess the potential of satclitcremote sensing in vegetation mapping of the Nilwala catchment area of Southernn SriLanka, The paper presents thc preliminary work amid at extracting vegctation informationfrom Landsat TM and ETM data, The maps produced applying image processingtechniques such as image differencing, Normalised Difference Vegetation Index (NIJVI),ISOCLUSS unsupervised classification and Tasseled Cap Transformation show the extent,quality and change of vegetation in the catchment area, Information derived from satellitedata can further be used in modeling erosion potential in agricultural areas, mapping theflood risk, and land cover and land use change analysis when combine with geographicalinformation,