Ecology, Environment and Conservation Paper

Vol 26, Issue 2, 2020; Page No.(785-792)

SPATIAL DISTRIBUTED EROSION MODEL BASED ON LAND SURFACE GEOMETRY : CASE STUDY IN SAYANG RIVER BASIN, MALANG DISTRICT

Bambang Suharto, Ifa Fajarika and A. Tunggul Sutan Haji

Abstract

Erosion is the process of drifting (losing) or overflowing soil because of pressure wind, water and human actions. Erosion causes topsoil eroded. The erosion process often occurs around of us, especially in agricultural land on the hillside. Sediment in watersheds is an indicator of damaged watersheds. Erosion caused a sedimentation process and make some sediment in the last process. Sediment will settle on the riverbed and part of the sediment will be carried into the reservoir. Generally, erosion prediction models have their advantages and disadvantages. Research of erosion prediction model is still being developed. Based on Moore and Burch’s (1986) equations, flux of sediment in an area can be calculated by the equation qsx= ktqx p+1 (sin)n where qsx is the sediments, p and n are exponents,  is the slope angle at x, kt is a characteristic of the river, from the derivation of sediment flux equation, is obtained Potential Erosion Index. Potential Erosion Index influenced by slope, flow accumulation and surface of the soil. Moore and Burch’s (1986) equation was applied to the sub-tropics climate so if it is applied to the climate of the tropics needed validation process. The purpose of this study is to modelling Moore and Burch’s (1986) equation in numerical form, integrate the geometrical erosion model with Geographic Information Systems (GIS) and apply the geometric erosion models in the Sayang river basin and create an erosion model based on land surface geometry factors from the calibration process expressed in the erosion index geometry and calculate the magnitude of erosion with analytic equations.