ANALISIS KEKRITISAN LAHAN UNTUK PERENCANAAN REHABILITASI LAHAN DAS SOLO BAGIAN HULU (Analyses of degraded land for rehabilitation planning in upper Solo Watershed)

Abstract

Water erosion is one of the causes of degraded land and a decrease in land productivity. Improvement of degraded land needs to detect sources of erosion and vulnerability level of the degraded land. The research was conducted to predict the vulnerability of soil erosion and distribution of degraded land in order to support the implementation programme of Land Rehabilitation and Soil Conservation. The research was conducted in upper Solo Watershed. Soil erosion was predicted using Universal Soil Loss Equation (USLE). The analysis of Land Capability Class was undertaken to determine the suitability of current landuse with its capability. Analysis of critical land was based on the regulations of the Directorate General of Watershed Management and Social Forestry (BPDAS-PS) Nomor 4/V-SET/2013. The data used were DEM (Digital Elevation Model) Aster (30 m x 30 m), map of the Regional Physical Planning Program for Transmigration (RePPProT) scale 1: 250,000, map of forest area (1: 50,000) from BPKH (Forest Zone Determination Center), land cover map from BPKH (1: 50,000), Google Earth imagery, rainfall data from 93 rain stations and field surveys. The results show that the upper Solo Watershed is dominated by land categorized as potentially degraded (54%), followed by slightly degraded (35%), while land which is classified as degraded occupied 7% of the total watershed. The dominant land capability is categorized as V th class and limited by soil erosion (89%). Dry land agriculture areas were found at land capability VI th and VII th which should not utilized for agricultural activities. Implementation of agroforestry and teracing are alternatives to prevent further land degradation and to improve the current condition.