Simulasi Debit Puncak dan Distribusi Aliran Sungai Ciliwung Hulu

Abstract

Daily discharge data of Ciliwung Watershed have been measured based on water level on Water Level Stations of Katulampa. Discharge of Ciliwung Watershed is contributed by its sub-watershed discharge. Discharge data of each sub-watersheds are not recorded, therefore sub-watershed discharge needs to simulate. The aim of this study is to simulate contribution of each sub-watershed discharge of Upper Ciliwung Watershed. The peak discharge was estimated using HEC-WMS v.8.1 with Soil Conservation Service - Curve Number (SCS-CN) method. The result showed that the simulated peak discharges has a good correlation with observed peak discharges, with the value of R2 is 0,701. RMSE is 15,55 with the lowest peak discharge is 8,23 m3/s and highest is 102,26 m3/s. The Upper Ciliwung Watershed is divided into six sub-watersheds, which are Tugu (4897 ha), Ciesek (2564 ha), Cisarua (2293 ha), Cisukabirus (1729 ha), Cibogo (1285 ha), and Ciseuseupan (1207 ha). CN of sub-watersheds are 74,0 for Ciesek, 72,5 (Tugu), 71,0 (Cisukabirus), 70,7 (Cibogo), 69,3 (Cisarua), and 67,9 (Ciseuseupan). The result showed that Tugu sub-watershed contributed the highest discharge (39%), then followed by 29% (Ciesek), 11% (Cisukabirus), 9% (Cisarua), 7% (Cibogo), and 3% (Ciseuseupan).