Prediction of The Depth Erosion in Rivers with Scale Models

Abstract

Flood is a disaster that often hits, especially urban areas, so that it can harm human activities and other living things. Palembang City itself has 108 tributaries. There are 4 (four) major rivers that cross the city of Palembang, namely the Musi River, Komering River, Ogan River, and Keramasan River. The drainage system of the city of Palembang, which always experiences flooding every year, includes the Buah river watershed. The Buah River, with the main river being 7.93 km long, has many meanders and a river wall reinforcement has been built.The research was conducted to see the flow phenomenon in the river with hydraulic modeling, namely by using the river/channel scale model in the hydraulics laboratory.The relative erosion depth (de/t) on the riverbed precisely at the mouth of the Buah river is 2.16 cm in the model with a significant level of R of 74.22% or 0.7422. This means that the speed (v) and time (t) simultaneously have quite an effect on the depth of erosion (de) that occurs at the mouth of the Buah river.Other factors that influence the magnitude of the depth of bottom erosion (bed load) at the mouth of the Buah river as the dominant variables are flow velocity (v), grain diameter (d), and changes in water level (h).