Analysis of River Discharge by MWSWAT Model on Several Landuse at Upper Citarum Watershed, West Java.

Abstract

Observation was conducted at Upper Citarum Watershed, West Java Province in area of 12.000 km2 The highest of landuse change was 1994 to 2005, where the forest had been change to other landuse. The result of calibrated SWAT model showed that the model was quite accurate to predict surface flow at Upper Citarum Watershed with Nash-Sutcliffe efficiency value of 0.714 and R. The purpose of this study were (1) to identify rate of landuse changes at Upper Citarum Watershed (2) to analyze river discharge by SWAT Model (3) to calibrate SWAT model with landuse 2001 (4) to validate parameters model with landuse of 1994, 1997 and 2005 (5) to analyze river discharge of calibrated SWAT model with land use of 1994, 1997 and 2001. 2 The analysis by calibrated SWAT model was done based on rainfall data in 2005 for landuse 1994, 1997 and 2001. The analysis result on landuse 1994 showed that surface flow was 112.5 mm and discharge rate was 76.7 m = 0.715. The calibration process was done by adjusting thirteen very sensitive parameters : Surlag ,MSK_Col1, MSK_Col2, MSK_X (.BSN), alpha BF, Shallst, GWQMIN, REVAPMN, GW DELAY (QW File), CHK2 (RTE File), CHNI (SUB File), EPCO (HRU File) and CN2 (.MGT File) . 3/s.The highest surface flow of 126.6 mm with discharge rate of 77.4 m3/s were obtained from analysis by calibrated SWAT model, landuse 1997 and rainfall in 2005. From analysis by calibrated SWAT model , landuse 2001 and rainfall in 2005 were obtained surface flow of 107.5 mm and discharge rate of 76.8 m3 /s

Peningkatan kebutuhan manusia akan lahan menyebabkan semakin meningkatnya perubahan lahan saat ini. Perubahan penggunaan lahan dengan intensitas yang lebih tinggi, yang sering tidak mengikuti konsep pengelolaan/penggunaan lahan berdasarkan konservasi tanah dan air. Perubahan penggunaan lahan khususnya daerah terbangun mengalami peningkatan yang pesat sehingga beberapa kegiatan akan bergeser ke daerah pinggiran. Tujuan dari penelitian ini adalah (1) mengidentifikasi laju perubahan penggunaan lahan pada DAS Citarum Hulu (2) menganalisis debit Sungai Citarum Hulu dengan menggunakan model MWSWAT (3) melakukan kalibrasi model SWAT berdasarkan landuse 2001 (4) melakukan validasi model SWAT hasil kalibrasi untuk landuse 1994, 1997 dan 2005 (5) menganalisis debit sungai model SWAT hasil kalibrasi berdasarkan curah hujan tahun 2005