ANALYSIS OF LAND DEGRADATION USING GIS (WITH SPECIAL REFERENCE TO WELIMADA DIVISIONAL SECRETARIAT DIVISION)

Abstract

Land degradation is one of the major global problems identified at present. According to the World Food and Agriculture Organization’s assessment of land degradation, about 50% of the total land in Sri Lanka has been degraded. In the Badulla District, it has been identified that 54.8% of the total area has been affected by soil erosion. Accordingly, the objective of this study was to identify the intensity of land degradation and the areas related to the Welimada Divisional Secretariat Division (DSD) located in the Badulla District. For this purpose maps such as soil map, altitude map, slope map, rainfall map and land use map are grouped. Subsequent maps were analyzed using the weighted overlay method. The final map was divided into five sections from very low to very high. Consequently, Ambewela and Alakolagala areas in the northeast corner of the Welimada DSD area and the Ohiya Estate and Maligawaththa in the south corner of the Welimada DSD were identified as high risk areas. According to the research, the highest risk areas were 1828.8 hectares, representing 9.48% of the total land area. Further, the high risk area was 10159.5 hectares which was 52.68% of the total land area. Accordingly, the area under the total area of the Welimada DSD can be identified as 11988.3 hectares and it was 62.16% of the total. Hence, the use of soil cover in the Welimada DSD area is very important. Farmers should also be directed towards measures such as raising awareness, providing high-tech services and adopting appropriate technologies.