Assessment of soil erosion in sub tropical ecosystem of Meghalaya, India using remote sensing, GIS and RUSLE

Abstract

Erosion is one of the major threats to the soils that limits its productive capacity. Soil erosion in Jirang block, Ri-Bhoi district of Meghalaya under sub tropical eco-system was assessed using revised universal soil loss equation (RUSLE) in geographic information system (GIS). In the study, IRS P6 LISS IV data of the study area was used to prepare land use/land cover (LU/LC) map by visual interpretation technique and digital elevation model (DEM) was generated from Cartosat-1 data, which was further used to develop slope, contour, flow direction and flow accumulation maps. Thematic raster layers of RUSLE factors (R, K, LS, C and P) were computed and used to estimate average annual soil loss in GIS (ArcGIS 10.0). The results showed that about 30% area is subject to severe (20.1-40.0 t ha-1yr-1) to extremely severe (>80.0 t ha-1yr-1). Based on the severity of soil erosion in the block, Umkadhar, Mokirson, Mauling and Dagiya Parbat villages have been categorized under high priority zone with severe (20.1-40.0 t ha-1yr-1) to extremely severe (>80.0 t ha-1yr-1). The soil erosion was found to be higher near to the 1st and 2nd order streams where soil conservation measures are imminent. The study demonstrated that use of geospatial technologies in combination with RUSLE is a comprehensive approach for spatial assessment of soil erosion for better resource planning.