Landuse allocation based on water resources conservation in Cisadane Hulu Sub Watershed

Abstract

Problems of land use in Cisadane Hulu sub watershed has led to a decrease in water resources, so that water resources conservation needs more attention. One of the efforts to conserve water resources is allocating landuse properly. For that reason a research was conducted at Cisadane Hulu sub watershed. The objectives of the research were (1) to identify the sub-sub watersheds performance, (2) to evaluate various alternative of the land use allocations, (3) to identify people preference about optimal land use, and (4) to formulate strategic direction of land use allocation. The methods of data processing analysis included spatial analysis, prediction of water discharge, and sedimentation that integrated in the AVGWLF model, and Analytic Hierarchy Process. The parameters used include Land Cover Index (IPL), the runoff coefficient (C), Erosion Hazard Index (IBE) and suspended sediment concentration (SC). Results of the analysis showed that in general Cisadane Hulu sub watershed has “Poor” performance. Among sub-sub watershed, 36 sub-sub watersheds had “Poor” performance and 8 sub-sub watersheds had “Medium” performance. To improve the performance, 3 scenarios were simulated, i.e. land use allocation based on Zone Function, based on Land Capability and based on RTRW. The Zone Function scenario produced the best result, followed by Land Capability and RTRW scenario’s. In the best scenario, Cisadane Hulu sub watershed was devided into 3 main areas with different of land use priority. Protected area is directed for forest, buffer area is directed for forest or mixed plantation and cultivated area is directed for rice field. AHP analysis show that people prefer to use buffer area for mix plantation and cultivation area for rice field. To implement the best allocation, policy strategies is necessary because of the mismatch between both of those results with the determination of the legally status of the area function, socialization, community empowerment and institutional strengthening.

Permasalahan penggunaan lahan di sub DAS Cisadane Hulu sudah mengganggu kondisi tata airnya, seperti ditunjukkan oleh adanya bencana banjir pada musim hujan dan bencana kekeringan saat kemarau di bagian hilir DAS Cisadane. Bencana lain yang tidak dapat diabaikan adalah erosi di bagian hulu, kualitas air yang menurun akibat meningkatnya sedimen tersuspensi dan sedimentasi di waduk, situ, muara sungai dan tubuh air lainnya. Hal ini menimbulkan banyak kerugian secara sosial, ekonomi, dan ekologi. Oleh sebab itu perlu dikaji penggunaan lahan di kawasan Daerah Aliran Sungai (DAS), karena efek negatif yang ditimbulkan tidak mengenal batas administrasi. Pengelolaan DAS bagian hulu menjadi sangat penting karena dari daerah inilah berawalnya proses yang terkait dengan hidrologi di dalam DAS.