Estimation of soil erosion for a semi-urban watershed in Tamil Nadu, India using RUSLE and geospatial techniques

Soil erosion is basically the land degradation form, which is the natural process that affects landuse (LU), agricultural productivity, soil fertility, and water availability. The present investigation aims the multi-temporal average annual soil loss of the Manimuthanadhi sub-watershed utilizing RUSLE (revised universal soil loss equation), Remote Sensing (RS) and geographical information system (GIS). The annual average soil loss has been predicted for the combined impact of rainfall and LU changes. The rainfall erosivity factor (R) generated for the years 2004 (dry), 2009 (normal) and 2010 (wet) and the corresponding period cover management (C) factor map also derived. The results revealed that the mean annual soil erosion rate of 54.50 t ha-1 yr- 1 in 2004. Soil erosion in 2009 is remarkably increased to 96.5 and 87.7 t ha-1 year-1 was observed in 2010 which is lower than in 2009. The erosion risk in the region increased by 43.52% from 2004 to 2009, whereas it reduced by 25.97% from 2009 to 2010. Further, the Prioritization analysis was carried out to identify the critical watershed, based on the results, Sub-watershed numbers 2, 6, and 8 were identified as very critical stages and require some conservation practices to control and manage soil erosion.