Analisa Pendugaan Laju Erosi Dengan Menggunakan Model Agricultural Non Point Source Pollution (AGNPS) di Sub Das Lesti Kabupaten Malang

Abstract

Changes in landuse and the topographic are undulating and hilly with a slope of 8-45%, as well as the intensity of precipitation impacts on increased erosion rates in sub-watershed Lesti area. Continuous erosion of land causes shallows rivers in Sub-watershed Lesti. An analysis and mapping of the greater existential rates on erosion and sedimentation along with the erosion of sub-watershed Lesti as well as land conservation efforts to reduce the effects of such erosion.Calculations using a model Agricultural Non-Point Source Pollution (AGNPS) obtained an average watershed erosion rate of 163,119 tons / ha / year. The results analysis of the danger erosion levels and area based on erosion danger index by hammer (1981) is obtained with a low level index (<1) 13,770 km2, a moderate level (index 1-4) 13,521 km2, a high level (index 4-10) 14,623 km2, and an exorbitant level (index >10) 16,342 km2. Based on sediment delivery ratio (SDR), results of sediment are 144,820.54 tons / year or 120,683.96 m3 / year. The conservation of land to reduce the rate of erosion are carried out in several ways, either by using vegetative and mechanical methods.