Modeling of Flood Prone Areas In The Kelara Watershed

Abstract

One of the efforts to minimize the negative impacts of flooding in the Kelara Watershed is to make model flood-prone areas that can be used as an initial reference for flood disaster mitigation. The analytical method used is hydraulic analysis using 2D HECRAS numerical simulations to determine areas affected by flooding based on flood discharge at a return period of 2 - 100 years. Based on the simulation results, it is found that the discovery area for Q2 is 331.42 Ha, Q5 is 547.21 Ha, Q10 is 798.76 Ha, Q20 is 925.11 Ha, Q25 is 925.79 Ha, Q50 is 1048.48 Ha, and Q100 is 1146.71 Ha. From the results of the flood depth verification, it was also known that the flood that occurred on January 22, 2019 was approaching the 100 year return period flood and June 12, 2020, was approaching the 20 year return period flood. So from the results of mapping and field verification, it is known that the 4 affected districts are Binamu District, Kelara District, Turatea District, and Biringbulu District with the location of the worst flooding occurred in Sapanang Village, Binamu District.