Studi Perubahan Penampang Sungai Bengawan Akibat Debit Banjir Menggunakan HEC-RAS

Abstract

The Bengawan River exhibits interconnected dynamics. As a result, erosion and sedimentation occur at various points along the river, especially after significant discharge events. HEC-RAS is a software developed by USACE that can simulate 1D sediment transport in rivers. The objective of this research is to analyze the changes in cross-sections of the Bengawan River due to the influence of a 100-year flood using HEC-RAS. The methods employed include the analysis of the 100-year flood discharge using HEC-HMS software and the analysis of cross-sectional changes using HEC-RAS. Based on the analysis, the peak discharge of the 100-year flood hydrograph is determined to be 35.85 m³/s. In the HEC-RAS simulation using a quasi-unsteady flow type with a duration of 48 hours, changes in river cross-sections were observed at stations STA 0+275, 0+250, 0+200, 0+175, 0+100, and 0+75. These cross-sectional changes were caused by sedimentation with thicknesses ranging from 0.13 cm to 2.08 cm