Analysis of soil erosion and its relationships with land use/cover in Tabunio watershed

Abstract

Erosion is detrimental to the health of the watershed exclusively in the upstream area of the watershed because it causes a lack of soil fertility because of being carried away by water, while in the downstream, it will reduce the river’s capacity due to sediment deposits. This research aims to determine the annual rate of soil erosion and its relation to land cover using the Revised Universal Soil Loss Equation (RUSLE). Factors needed by RUSLE in estimating erosion include rain erosivity (R), Soil erodibility (K) length and slope (LS), land cover processing factor (CP), and the value of 0,61 as correction factors. We classify the result shows that the erosion rate in Tabunio watershed into five erosion classes, ranging from very light to very heavy classes. The erosion rate in the Tabunio watershed ranged from 0,000158 tons ha-1 year-1 to 9.453,6 tons ha-1 year-1. Very mild erosion occurred in 59.06% of the total area, mild erosion covered 18,80%, while moderate erosion occurred in an area 7,78%, the level of heavy erosion covers an area of 8,15%, while very heavy erosion occurred in an area of 6,21% of the total area of the Tabunio watershed. Forest dominates the erosion rate in the very mild class, the light class until the hefty class is dominated by plantation followed by settlement and mine. From this research, it is known that land cover and land use do not significantly affect the rate of erosion.