Erosion Prediction and Soil Conservation Planning in Lawo Watershed Indonesia

Abstract

Land conversion from forest to agricultural land is a serious problem in Lawo Watershed. Agricultural practices without implementing the adequate of soil conservation and agrotechnology has led to high erosion and decrease land productivity. Management of Lawo Watershed is should be made by integrating the soil and water conservation and the increament of agriculture production. The aim of this study is to analyze the prediction of erosion and arrange the land use and soil conservation planning which actual erosion (A) is greater than tolerable eorion (T) in Lawo Watershed. USLE equation and Erosion Hazard Index is used to predict the erosion and soil and water conservation planning in the location. The results showed that moderate rate of surface erosion is dominant in the location which area of 18,804.64 ha (53.46%), which is generally spread in the center of watershed, while tolerable erosion is varies between 17.56 - 54.77 ton ha^-1 thn^-1 in each land unit. Erosion hazard index is the ratio between erosion predictions on each land unit with tolerable erosion in the same land unit. Index erosion which is moderate, high and very high category is dominant with total area of 19,347.66 ha (55%), this condition indicates that A value is higher than T. Therefore, it is need to manage the land unit in Lawo Watershed through land use planning and apply the soil conservation, so that the sustainability of land in the watershed can be reached. Land use planning that suggested are reforestation of shrubland area and development of agroforestry in mixed farming, while soil and water conservation that recommended are bund teracce and garden terrace combined with teracce strenghtening crop as well as mulch of 6 ton ha^-1 in slope 0 – 8%.

Keywords: USLE, Soil Erosion, Watershed, Erosion Index, Soil and Water Conservation.