Study on the Dynamic Correlation between Water-level and Reservoir Capacity of Poyang Lake Based on EFDC

ABSTRACT Reservoir capacity is a key parameter for lakes and reservoirs. To facilitate the quick and accurate calculation of the reservoir capacity of lakes, especially those with large area and complicated floor topography, a two-dimensional hydrodynamic model based on the Environmental Fluid Dynamics Code (EFDC), was developed for Poyang Lake. This model, based on the lake topography data of Poyang Lake collected in 2010, can accurately simulate the reservoir capacity of Poyang Lake. The simulation results revealed that, the water level at Xingzi, Duchang, Tangyin and Kangshan Station and the reservoir capacity of Poyang Lake exhibited relatively good correlation (with R2 > 0.90), exceptforTangyinStationinnormalanddryyears.Thevariationinreservoircapacity,whichis very significant from rising stage to recession stage of each typical hydrological year, was relatively minor for Tangyin Station. The correlation equation between water level and reservoir capacity of Poyang Lake was established respectively for wet, normal and dry year (R2 >0.95) by means of fitting, to minimize the influence of factors like lake surface gradient. This model enables more accurate and quicker calculation of the reservoir capacity as well as the dynamic reservoir capacity of Poyang Lake at present and in the future (after poyang lake water conservancy hub project is completed). In addition, the method provided a theoretical reference for accurate, dynamic and quick calculation of the reservoir capacity for other lakes and reservoirs.