The 24th IAHR-APD Congress (24th IAHR-APD Congress)

431 / 2024-03-15 23:09:19

Study of the Hydrodynamic and Thermal Behavior of Fuxian Lake Based on EFDC

Fuxian Lake; Thermal behavior;Numerical study; EFDC

Subtheme 3: Eco-hydraulics and Environment > Topic 2: Water Eco-environment Monitoring and Simulation

This study focuses on Fuxian Lake, the largest freshwater deep lake in China, and carries out numerical solution and quantitative analysis of hydrodynamics and thermal stratification phenomena. A three-dimensional hydrodynamic model was established using the high-fidelity Environmental Fluid Dynamics Code (EFDC) model, which accounted for variations in bottom elevation, and was preliminarily validated using measured data. The simulation results obtained are as follows: Firstly, the spatiotemporal characteristics of the thermocline are strongly influenced by meteorological conditions and hydrodynamic processes. Wind speed and water temperature differences primarily affect water flow, with the maximum values of water temperature and thermocline strength typically occurring in September. Secondly, vertical circulation is caused by wind-driven horizontal divergence and convergence of lake currents, leading to upward and downward movements of the lake currents and resulting in the heterogeneity of the thermocline. The study results show that the EFDC model can adequately reproduce the observed spatiotemporal variations, laying a foundation for the future coupling of the EFDC model with water quality models. Moreover, the significance of this study lies in providing an effective method for researching the lake hydrodynamics and thermal stratification processes of other deep lakes worldwide and offering assistance for lake management, ecological restoration, and other projects for other deep lakes around the world.