FUZZY MULTI ATTRIBUTE DECISION MAKING FOR RIVER BASIN MANAGEMENT

Mamasa River Basin is situated in South Sulawesi, Indonesia. In the recent years, the function of this basin can not be performed optimally in maintaining sustainability hydrologic function of Garugu dam. It is indicated by the occurrence of floods in rainy season and in contrary water shortage in dry season. Unexpected hydrology functions can be attributed to inappropriate land use at the upstream. Therefore, in order to maintain the hydrologic function of the dam, it is necessary to formulate suitable landuse at upstream of the river basin. This research is objected to formulate the suitable landuse, in term of reducing sedimentation rate in Garugu dam. This study employed RUSLE (Revised Universal Soil Loss Equation) for calculating erosion as well as sedimentation rate. Fuzzy Multi Attribute Decision Making (FMADM) and Analytic Hierarchy Process (AHP) which is combined with Geographical Information System (GIS), that ware used to formulate optimum landuse at the upstream. Focus Group Discussion (FGD) was conducted in order to validate the obtained landuse model using FMADM formulation. The optimum landuse is: composition for Mamasa River Basin that control of dead storage of sediment (DSS) is: 38.01% of agroforestry, 17.88% of forest, 15.66% of mixed agriculture, 11.30% of mixed garden and forest fruit crops, and the rest of the conservation actions and landuse such as strip cropping, rotation of crops, use bench terrace in rice fields, reforestation, cover crops and coffee plantation. The optimal landuse composition can control the sedimentation rate up to 127.22 (m3/km2)/yea