Asep Sapei

Discharge Analysis Using SWAT Model At Cipasauran Watershed, Banten

Total water demand at non industrial and industrial region in Cilegon is increasing. With its water production capacity of 2,000 l/s, PT Krakatau Tirta Industri (KTI) cannot fulfill the amount number of demand from the industrial and domestic sectors at Cilegon. To cover the shortage of water supply of ±600 l/s, PT KTI requires taking water from Cipasauran Watershed. The objective of this study was to analyze river discharge of Cipasauran Watershed using SWAT model. Input data such as soil characteristics, climate data, landuse, and hydrology data at the area of the watershed were gathered and put at the data input file. In SWAT simulation, 4 processes were done, i.e. watershed delineation, hydrological response unit (HRU) forming, data process and SWAT simulation, and visualization process. The result showed that the daily and monthly calibration process crossed 84% and 83% with the 95PPU area, with daily and monthly p-factor value of 0.84 and 0.83. Thus, calibrated model result was valid, though R2 and NS value were not satisfied. Using the validated SWAT model, the daily discharge in Cipasauran Watershed was about 0 3.309 m3/s, whereas the monthly discharge was 0.648 3.266 m3/s. This showed that daily and monthly PT KTI’s water demand of 0.6 m3/s were fulfilled about 98.22% and 100%. Within the future time, the SWAT model could be potentially used as an assessment for predictive scenarios. However, to gain optimum results, well-observed and precise data is highly required, especially for such calibrations and validations.

PENGEMBANGAN KEBIJAKAN PENGELOLAAN AIR BAKU BERKELANJUTAN DI SUB DAS KONAWEHA KABUPATEN KONAWE SULAWESI TENGGARA

Penurunan ketersediaan air akibat perubahan penggunaan lahan telah terjadi di Kabupaten Konawe, sedangkan permintaan air cenderung meningkat. Dari segi keberlanjutan penyediaan air, hal ini cukup mengkhawatirkan. Penelitian ini bertujuan menganalisis: (1) tingkat keberlanjutan, (2) faktor penting yang memengaruhi keberlanjutan, (3) peran kelembagaan dalam pengelolaan air baku berkelanjutan di Sub DAS Konaweha. Hasil analisis Multi Dimensional Scalling (MDS) dengan Rap-Konawe menunjukkan bahwa status keberlanjutan pengelolaan air baku di Sub DAS Konaweha kurang berkelanjutan dengan indeks 41,40%. Nilai indeks berkelanjutan diukur pada 5 dimensi yaitu ekologi, ekonomi, sosial, teknologi dan kelembagaan dengan nilai indeks masing - masing secara berurutan 52,36%, 36,93%, 34,16%, 35,39% dan 35,39%. Hasil analisis Interpretative Structural Modelling (ISM) menunjukkan tiga unsur yang perlu diperhatikan yaitu kendala, kebutuhan, dan lembaga. Kendala penting yang dihadapi adalah penurunan fungsi daerah tangkapan air karena berkurangnya vegetasi dan kurangnya koordinasi pengelolaan sumber daya air antara para pemangku kepentingan. Kebutuhan program yang harus menjadi fokus perhatian adalah peningkatan pengetauan dan keterampilan personil kantor pemerintah, serta peningkatan kesadaran stakeholder . Adapun lembaga yang menjadi faktor kunci untk program ini adalah BPDAS Sampara dan Dinas Kehutanan Kabupaten Konawe.