基于EFDC模型对鄱阳湖湖面面积的推算方法

Poyang Lake area estimation based on EFDC model

鄱阳湖是中国最大的淡水湖泊,水位与面积是湖区生态系统中的重要参数.主要研究鄱阳湖水位与面积的数学关系,以便用水位来快速推求湖面面积.利用美国EFDC水动力学模型对典型年份面积进行模拟,得出逐日模拟面积,而后根据康山、棠荫、都昌和星子4站实际水位与模拟面积建立数学关系,最后使用遥感数据对模拟面积进行验证.结果表明,典型年份鄱阳湖水位与面积具有高动态性,平均相对误差为4.14%,模拟面积与实际面积误差较小.

Poyang Lake is the biggest freshwater lake in China,where water level and surface area are crucial parameters to the lake ecosystem.This paper studies into the mathematical relationship between water level and area of Poyang Lake,with purpose to estimate the lake area by water level through model simulation. The EFDC（ Environmental Fluid Dynamics Code） hydrodynamic model is used to simulate the daily variation of Poyang Lake area in typical hydrologic years.Then the statistical relationship functions are developed between simulated surface area and actual water level data which were collected from four hydrologic observation stations including Kangshan,Tangyin,Duchang and Xingzi.Furthermore,the statistical relationship is verified by remote sensing data. The results indicate that the water level and area of Poyang Lake are highly dynamic during typical hydrologic years,yet the EFDC based method can estimate the Poyang Lake area with relatively high accuracy,with the average relative error being 4. 14%.