Estimation of soil erosion by RUSLE model: a case study of Situ Ciseupan area, West Java

Abstract

Situ Ciseupan is a natural pond which the areas surrounding it are bordering with conservation area (Mount Papandayan Nature Park). The area is expected to function as buffer zone, yet local communities utilize this area for agricultural activities, which plays important role in their economics. Such condition creates high risk of erosion that could lead to decline in soil fertility as well as water quality of the pond and nearby streams. This study aimed to estimate the rate of soil loss in Situ Ciseupan area under the current land-use/cover (LU/LC) patterns and hypothetical LU/LC patterns for exploring the impact of land-use/cover conversion on soil loss. Soil loss rate is estimated using the Revised Universal Soil Loss Equation (RUSLE) model. The study shows that average soil loss rate under the current LU/LC is 35.3 tons/ha/year. Areas classified as very high and severe erosion contributes 64.71% of the total soil loss. For simulating the impact of LU/LC conversion, we developed five scenarios in which the current LU/LC is converted into five hypothetical LU/LC types, each consists of a single type of LU/LC, i.e. bare soil, settlements, grassland, agriculture land, and forest. The simulation results show that if the current LU/LC is converted into 100 % of bare soil, settlement area, grassland, and agricultural field, the soil loss rate will increase by 1163%, 873%, 520%, and 317%, respectively. In contrast, the soil loss rate will decrease by 93%, if the current LU/LC is converted to 100% forest.