Application of three-dimensional hydrodynamics and water quality model of the Youngsan River, Korea

Abstract

A B S T R A C TThere have been major changes in flow pattern in the Youngsan River due to construction in-stream structures including newly built Seungchon Weir and Juksan Weir in the middle of the river in addition to existing estuarine dam. Increased nutrient load from basin area has been a major cause of repetitive algal blooms in the river. And increased residence time due to the construction may affect growth dynamics of phytoplankton in the river. This paper reports the construction of a mathematical model to predict phytoplankton dynamics in the area for evaluation of various future management scenarios. The Environmental Fluid Dynamics Code model was chosen as a three-dimensional hydrodynamics and water quality model. Hydrodynamics model and water quality model were successfully calibrated using observed water level data and water quality data, respectively, in selected locations in the river. It is expected that the developed model can be successfully applied to select appropriate water quality management alternatives.