Economic Sediment Transport Control with Sediment Flushing Curves for Sea Dike Gate Operation: Case Study in Saemangeum Basin, Korea

As the major reclamation works in Korea, the sea dikes have been installed for preventing the saltwater intrusion in Saemangeum Basin connected with Mangyeonggang and Dongjingang River, Korea since 2010. Recently, the sedimentation issues near the gates due to change of flow velocity might induce serious problems such as water pollution, local scour, stability of hydraulic structures linked with dike. We focused that the gate operation rule was changed to alleviate the sediment transport problem by altering the management water surface elevation in this study. The 3D numerical model, SCHISM, was used to simulate the sediment transport under the gate operation rule which was embedded after modifying the hydraulics structure module in SCHISM. The numerical model was verified by comparing with the measured data in the literature. It was found that the phenomenon induced by gate operation was accurately simulated to compare with the field measurements from Korea Rural Community Corporation (KRCC). Based on the results of SCHISM, the Best Management Practices on gate operation were examined and suggested the optimal solution in terms of structural stability and water use including water quality.