The application of Rainfall-Runoff-Inundation (RRI) model for inundation case in upper Citarum Watershed, West Java-Indonesia

摘要

The upper Citarum River watershed which located in West Java-Indonesia, has been suffered from flood occurrence every year during the rainy season because it is a plateau area surrounded by the mountain. In order to prevent and mitigate flood damage, it is necessary to understand the characteristic of the flood, however, the local areas often suffer from a lack of the hydrological data. Therefore, an approach to estimate the flood inundation area using satellite-based rainfall instead of the limited hydrological data is proposed. To reproduce the largest 2010 flood in the upper Citarum River Watershed, Rainfall-Runoff-Inundation (RRI) Model, which consists of tightly coupled a two dimensional rainfall-runoff and inundation model, was utilized. As an input data, 15 arc-second HydroSHEDS Digital Elevation Model (DEM) and satellite-based hourly rainfall data (GSMaP), which is validated by comparing with the daily observation data, are used. Simulation results are compared with the observed water discharge at the outlet, Nanjung water stage gauging station, and observed inundation area provided by Upper Citarum Basin Flood Management (UCBFM) Team in the year 2010. Although the simulated inundation area showed a good agreements with the observed one, the simulated discharge showed some discrepancy because of the uncertainties involved in the observed discharge and the deficit of the input data for simulations.