Rainfall-runoff modelling for Ciliwung Watershed in West Java, Indonesia

Abstract

The transformation of rainfall into runoff within a watershed system is influenced, to a great extent, by the watershed characteristics. Logically, a rainfall-runoff model developed by considering the watershed systems in the nature may provide abetter representation of the system compared to the modified tank models developed by considering the infiltration process in the modified tank model as the phenomena in the Ciliwung Watershed. In this study, a modified tank model of the rainfall-runoff process to predict daily runoff was developed and applied for Ciliwung Watersheds, comprising an area of 14,876 Ha. The hydrological data collected are the secondary data, and primary data of infiltration rate. The average coefficient of correlation is 0.82 for the model calibration and model validation in 1994, 1995, and 1996, for Ciliwung Watershed and 1996, 1997 for Cidanau Watershed. The results of this study indicate that the simulations of daily runoff were in close agreement with the corresponding observed of Daily River Runoff Discharge