Estimation of soil loss by using remote sensing and geographical information system

Abstract

Soil loss is the total amount of soil particles that reaches the watershed outlet due to erosion and deposition processes within a watershed. It results in the erosion of nutrient-dense topsoil in elevated regions, leading to a decline in agricultural production in such areas. Also on bed of river and lakes due to increase in sedimentation reduces the capacity of river, which increases velocity of the water leading erosion downstream and in coastal zones and cause damage to coastal and marine ecosystems and human settlements. Hence, soil loss is needed to estimate for studies of reservoir sedimentation, river morphology and soil and water conservation planning. The present study aimed at estimating soil loss USLE equation using remote sensing and GIS technique in Urun Islampur watershed, located in Walwa tehsil, Sangli district of Maharashtra, occupying an area about 67.66 km2. Watershed boundary and LULC were generated in GIS platform by using existing soil map. The slope is derived by using “Show Slope Profile” in “Google Earth” software by using boundary of watershed. The ultimate soil loss is determined by multiplying all derived and computed parameters utilizing the USLE equation. The estimated soil loss of the Urun Islampur watershed using USLE equation in 2001 was 4.148 t/ha/yr. However, it was found 0.712 t/ha/yr for year 2008 with a decrease of 3.436 t/ha/yr. USLE equation is suitable for the Urun Islampur watershed for estimation of soil loss. The decreased soil loss was observed to the extent of 3.436 t/ha/yr (82.83%) in seven years i.e. from 2001 to 2008.