Erosion rate prediction model ssing SWAT and CA-Markov methods (case study: Upper Ci Catih Catchment Area)

Abstract

Landuse has a vital role that affects the movement of water on hidrological cycle. Around Upper Ci Catih Catchment Area in the past 10 years, many of various industries (ranging from smal-scale to large-scale industries) have increased. Increasing built-up area, especially settlements and industries can increase runoff that have an impact on land degradation such as erosion. This study focuses on the hydrological modelling made by SWAT (Soil Water Assesment Tools) and landuse change prediction using CA-Markov (Cellular Automata-Markov Chain) to find the effects of landuse changes on the erosion rate changes. Erosion rate prediction in 2032 based on landuse changes prediction in that year. This study shows that variations of Hydrologic Response Unit (HRU) conditions affects the erosion rate in every subwatershed. The result of accuracy and calibration test satisfied, which NS and R2 mark for SWAT validation is 0,56 and 0,72, and kappa coefficient value for CA-Markov model validation by 89%. The changes of landuse especially forest and irrigated rice fields is predicted in 2032 will decrease in every Subbasin. It will affect the increase of average erosion rate in every Subbasin by 15% of the erosion rate in 2017 on Upper Ci Catih Catchment Area.