Analisis Angkutan Sedimen Dasar (Bed Load) Dengan Pemodelan HEC-RAS 6.0

(Studi Kasus Sungai Cimulu Kota Tasikmalaya)

Abstrak

Tasikmalaya City has several rivers, one of which is the Cimulu river, which flows from the Cibunigeulis area and empties into the Ciloseh river. Along the Cimulu river there are several problems including silting and reduced flow speed caused by sedimentation. The purpose of this study was to determine the amount of bed load transportation that occurred in the Cimulu river using the Yang method and the Engelund and Hansen method and to determine the modeling of HEC-RAS applications in the analysis of bed load transportation of the Cimulu river.This study uses quantitative methods by making direct measurements in the field and taking sediment samples from three points, then tested in the laboratory to determine the d_50 and specific gravity of sediment used for data analysis. Calculation of sediment transport using the Yang method and the Engelund and Hansen method. The calculation of sediment transportation in the Cimulu river using the Yang method is 58.86 m^3/day and using the Engelund and Hansen method is 30.383 m^3/day. So the percentage difference with the two methods is 28,477 m^3/day.Meanwhile, based on the simulation results using HEC-RAS 6.0 in the period of July 1 – August 1, 2023, it can be known that the bed load discharge is 16.31 tons. Based on the sediment data output of the running results, it can be seen that changes in riverbed rivers occur at sta 0 + 4651.96 and sediment deposition occurs as high as 0.0431 meters, then degradation occurs downstream as deep as 0.0031 meters.