Predicting the impact of land-use change on soil erosion rate in Ussu sub-catchment area and sedimentation yield in Malili River

Abstract

This study aims to predict the impact of land-use change in Ussu sub-catchment area during the last ten years on the rate of soil erosion and sedimentation yield in the Malili River. The USLE method was used to predict soil erosion rates in 2009 and 2015 using DEM data, Landsat 8 Image, station rainfall data, and land use. Sediment yield was determined using flow rates calculated using the spline cubic interpolation method, the SDR of the water sample was verified by the equations developed by SCS, Vanoni, Boyce and Auswald based on the suitability of the measured surrounding sub-watershed. The results show that soil erosion rates have increased in the period of 6 years. The erosion rate increased from 58,693 tons in 2009 to 155,136 tons in 2015. SDR value was obtained at 0.1894, so the potential sedimentation in the Malili River was predicted to a maximum of 1.57 cm in 2009 and 4.15 cm in 2015. Contributions of soil erosion on sedimentation have occurred as the impact of the increased deforested land around 654.8 ha.