Comparison of ROMS and EFDC sediment transport models at an altered Nakdong River estuary, Korea

초록

Over the last century, estuaries have been heavily altered by various human activities such as sedimentation from soil erosion and diking or damming for flood control or water diversion. Sediment transport models are valuable tool not only to understand physical processes and morphologic changes operating in altered estuaries, but also to manage estuarine environments. Although models have been applied to many estuaries for various purposes, inter-comparisons of 3D sediment transport models are rare. In this study, we compared two numerical sediment transport models, ROMS (Regional Ocean Model) and EFDC (Environmental Fluid Dynamics Model), at an altered Nakdong River estuary, Korea. To examine the performance of two models, we used same bathymetry, horizontal and vertical grids, boundary conditions and inputs such as tide, winds, river discharge, and waves. Two models also used SWAN (Simulating Waves Nearshore) for the wave module, but utilized their own hydrodynamics and sediment transport modules. The model calibration was carried out with in-situ data of sediment transport measured at the river mouth of the Nakdong estuary in 2011. The model simulation was then used to compare and investigate the efficiency of the two sediment transport models on the site of Nakdong estuary during a large discharge event.