EVALUATION OF SOIL EROSION SENSITIVITY USING REMOTE SENSING AND GIS: A CASE STUDY IN KANCHANABURI, THAILAND

Abstract

The advantage of a combination of Remote Sensing (RS) and Geographic Information System (GIS) techniques has great potential for supplying databases on natural resources management. In this study, the area 15x15 km in Thong Pha Phum district, Kanchanaburi province was investigated for soil erosion sensitivity. Five erosion factors were used for the production of an erosion hazard map. It consists of: 1) slope gradient; 2) soil erodibility; 3) drainage density; 4) vegetation cover; and 5) conservation practices. The interpretation of LANDSAT TM dated 12 December 1989 for the delineation of land use patterns provided a vegetation factor. Field trips were also conducted for map verification and data collection. The integration of these five erosion factors was performed on the digital GIS. The results showed that 63.5% of this area was flat (0-2% slope) and the land use types mostly dominated by the intensive of agricultural crops without a conservation practices. The final erosion sensitivity map mostly showed a low and moderate level which correlated very well to the field observation. Since, there are signs of rill erosion and shifting cultivation in this study area, we suggested that the serious erosion problems may occur in the near future.