Mapping of Flood-Prone Locations Impacted by Cilember River Overflow in Cimahi City Based on Geographic Information System

Abstract

Abstract The high intensity of rainfall in Indonesia has a potential to cause catastrophic flooding in Cimahi City which is geographically located in the valley of basin and causes the overflow of water to the Cimahi City. There are nine flood points in Cimahi City and eight of them are located near Cilember River. This research creates a 2-dimensional map of flood-prone location impacted by Cilember Riveroverflow. The map is integrated by constructing a Geographic Information System (GIS) not only at flood point location, but also at point of the existing survey, point of the river crossing measurement, and river crossing point location at each STA with the information of location coordinates, flood depth, flood solutions, and images. Data processing begin with hydrological analysis that will be used for hydraulic analysis using HEC-RAS software and flood-prone map using ArcGIS software. The map is processed and become GIS that built in ArcGIS software. This research product is a flood-prone map impacted by Cilember River overflow in period of 2, 5, 10, 25, 50, and 100 years based on the GIS. The difference of flood distribution generated in each return period does not appear significantly, but it can be seen at the height of flood in every return period. The benefit of this research is to provide information on the vulnerability of flood area to Cimah iCity Government to solve flood problem that occur almost every year in Cimahi City.