Flood hydrograph simulation to estimate peak discharge in Ciliwung river basin

Abstract

Ciliwung River Basin is one of 13 watersheds located in the Special Capital Region of Jakarta (DKI Jakarta), one of the most vulnerable cities facing flood disaster. Modeling hydrographs in a flood computer model is a crucial process in understanding the hydraulic processes in floods; however, more often than have adequately not studied watersheds do not available observed data. Well-calibrated hydrographs serve as the basis for a basin-wide flood model. In this study, the Snyder, ITB, and SCS Unit Hydrograph are constructed in the study case of flooding in the Ciliwung River Basin, with West Java rainfall distribution method and Alternating Block Method as the adopted rainfall distributions, providing six combinations of approaches. Calibration and validation analysis show a combination of West Java rainfall distribution and SCS UH with a lag time of 5.5 gives the smallest deviation, with an accuracy of 83.3%, therefore it is recommended for use to estimate design future flood hydrograph.