Hydraulic Analysis on the Hydrodynamic Pattern Change with Weir Removal Using HEC RAS model: A Case Study in Geum River, South Korea

In general, the purpose of installing the river structure is to secure the water depth through the structure. This ultimately increases the usability of agriculture and domestic water, and increases flood water reserves to reduce downstream flood damage. We tried to compare the water depth with respect to the weir removal and operation. And we chose the Geum among 4 major Rivers. The Geum River is located at 58.75 km (Baekjae weir), 81.72 km (Gongju weir), and 100.66 km (Sejong Weir) from the downstream. We will explain the structural features of the three weir of the Geum River and explain the hydraulic theory for analyzing the results. It also describes the role of each weir and the side effects of installing weirs. The experimental method is as follows. After obtaining the data of Geum River, the structure of Geum River is grasped through HEC-RAS model. Configure weir before and after installation via inlet structure data in geometric data. After that can analyze the results through compute and view the water depth and cross-sectional velocity change before and after the installation of the weir through the water flow and graph through the profile view.