鄱阳湖流域分布式水文模型的多目标参数率定

以鄱阳湖流域为研究区，构建其分布式水文模型WATLAC。以鄱阳湖流域6个水文站点2000～2005年河道径流量及地下水基流指数为多目标函数来优化耦合模型，采用PEST进行WATLAC模型参数自动率定。结果表明：6个水文站点拟合的纳希效率系数变化范围为071～084，确定性系数介于070～088，取得较好的模拟效果。基于遥感反演的实际蒸散发结果进一步验证模型，模拟值和遥感反演值在时间和空间上的变化趋势呈现较好一致性。基于地下水位及流场特征模拟效果的定性评价，表明地下水位模拟空间趋势性较好，水位与地面高程的空间变化一致，地下水主要以下游平原区和河道为主要排泄区，符合大尺度流域地下水流运动基本规律和评估结果。所提出的多目标率定方法及率定技术应用于大尺度鄱阳湖流域，也为其它水文模型在相似区域的连续模拟及参数率定方面提供借鉴。〖HJ1〗〖HJ〗

MULTI-OBJECTIVES MODEL CALIBRATION FOR DISTRIBUTED HYDROLOGICAL MODEL IN THE POYANG LAKE WATERSHED

This paper used the Poyang Lake watershed as the study area, and a distributed hydrological model was set up for this area The observed river discharges at six main hydrological stations from 2000 to 2005 and the base flow index of groundwater were used to establish the objective functions for coupled model optimization PEST was used as an auto calibration tool embedded in WATLAC to improve the efficiency of model calibration Results showed that the Nash sutcliffe efficiency coefficients of different hydrological stations were varied from 071 to 084, and coefficients of determination were varied from 070 to 088, a better simulation effect was gained The actual evapotranspiration （ETa） based on remote sensing was further used to validate the model Results indicated that model simulated and remotely sensed ETa match well in terms of the spatial variation pattern and the temporal change trend Furthermore, groundwater flow model was estimated qualitatively, and it was found that the spatial variation of water table was in consistent with the land surface elevation The general flow direction was from the mountainous areas to the plain area, which was judged as reasonable The model calibration strategy and technique proposed in this paper can provide high reference for similar studies in a large scale watershed simulation and parameter calibration.