Modeling and Simulation of Flow through The Construction of River Cover Embankment: Case Study of Sei Wampu Weir, Langkat Regency, Indonesia

Abstract

Sei Wampu Weir construction project faced problems related to river cover embankment work, where the river cover embankment experiences scouring on the riverbed during flooding. The purpose of this study is to simulate flow model and determine the maximum flow speed, hence, the appropriate structure of cover concrete blocks can be determined. The analysis of water availability in this study used the F.J. Mock method by considering the watershed area, rainfall data, climatological data, evapotranspiration, and other supporting data to obtain 80% of the mainstay. Modeling and simulation of flow through river cover embankments was performed using the Hec-Ras 5.0.7 program with three scenarios. The determination of Locked Concrete Blocks as a handling solution refers to the Scientific Manuscript of Locked Concrete Blocks as Riverbed Control Buildings of the Water Resources Center in 2014. Results found the mainstay discharge analysis of 80% in year 2020, which was 139.10 m3/s. The model results in the first scenario (width of the river still open about 85 meters) obtained a flow speed of 2.04 m/s, the second scenario (width of the river still open about 30 meters) obtained a flow speed of 2.48 m/s, and the third scenario (width that was still open about 10 meters) obtained a flow speed of 4.34 m/s. The locked concrete blocks for the first scenario used the six-foot locked concrete block type, whereas the second and third scenarios used the eight-foot locked concrete block. Based on numerical modeling and analysis results of locked concrete blocks, the appropriate and efficient scenario for closing the river cover embankment in the sei wampu weir construction project is the second scenario.