Aplikasi hidrograf satuan sesaat Geomorfologi/GIUH untuk memprediksi debit sungai: studi kasus DAS Cibojong

Abstract

One application of the concept of geomorphological instantaneous unit hydrograph/GIUH is to predict the flow of river that have no discharge gauge stations in the field (Ungauged Basin). The study was conducted through analysis of watershed geomorphology characteristics of digital elevation model (DEM) data using the program from Environmental Systems Research Institute/ESRI (ArcView GIS Software Version 3.3). After getting the parameters characteristic watershed geomorphology and net rainfall based on watershed area and then simulated using the model of H2U (Hydrogramme Unitaire Universel) to obtain the discharge simulation. Field discharge measurement data obtained from the automatic water level recorder (AWLR) data and rainfall data obtained from the data Automatic Weather System/AWS, both types of data were analyzed by using the aid program CIMEL Elektronique’s Automatic Weather Stations Management (CimSta’s Software) and Microsoft Office 2007 software programs. To compare the quality of the simulation results from the discharge and discharge in the field measurement results are validated by the F test (Nash and Sutcliffe 1970). Discharge simulation obtained from the four episodes in watersheds selected Cibojong resemblance to discharge measurements in the field. Episode December 23th, 2006, February 3th, 2007 episode, July 16th, 2007 episode, and October 25th,2007 episode of each F test value respectively 0.67, 0.89, 0.77, and 0.66. The tests are conducted to predictable streamflow in Cibojong Watershed.