基于SWAT模型分析淮河流域中上游水量平衡要素对气候变化的响应

本研究在对SWAT模型进行参数化的基础上，采用淮河干流吴家渡和鲁台子水文控制站1971-1990年和1991-2014年的月径流观测数据对SWAT模型进行了率定和验证。模拟效果评估结果显示：不论是率定期还是验证期，Nash-Sutcliffe系数Ens和确定系数R2均>0.8，相对误差Re<1%，模型能够较好地再现月尺度的降雨-径流过程。淮河中上游年径流深线性变化趋势不明显，但子流域空间差异显著，径流深上游及南部呈线性减小趋势，其他子流域呈增大趋势。从年水量平衡要素来看，蒸散量和渗漏量对水量平衡贡献最大。主成分分析表明，平均气温、降水量及蒸散量是淮河中上游水文要素变化的关键因子。剔除人为因素的影响，1971-2014年淮河中上游地区水资源量呈减少趋势，这可能是年平均气温升高、年降 水量略有减少以及年蒸散量减少综合作用的结果。本文研究成果可为淮河中上游水资源管理和相关政策的制定提供技术支撑。

Water Balance Response of the Climatic Change Based on SWAT Model in the Upper-Middle Reach of Huaihe River Basin

Huaihe River basin is located in central-eastern China, and it stands between the south-north climatic transitional zone. Varied kinds of weather systems mutually interlock and mutually effect, which forms a typical ecologically fragile area, and Huaihe River is also a sensitive area of climate change. In order to fully understand the impact of climate change to runoff in the upper-middle reach of Huaihe River basin, the paper applied the data of monthly runoff from 1971 to 1990 for the calibration and the data from 1991 to 2014 for verification by using automatic adjusting and parameters adjusting of SWAT model. The evaluation results showed that the Nash-Sutcliffe efficiency coefficient and linear determination coefficient were more than 0.8, and the relative error of simulation (Re) was less than 1%, indicating that the model could effectively reproduce the rainfall-runoff process of monthly scale. The annual runoff depth didn’t show obvious linear trend in general, while the upstream and the southern part of the runoff depth of the sub-basin were linear decreasing, and other areas were increasing. The annual evaporation and water percolation past bottom of soil profile in watershed for the year contributed more to the change of annual water balance elements. The average temperature, precipitation and evaporation were the critical factors of the changes of hydrological elements in the upper-middle reach of Huaihe River basin using principal component analysis. Eliminating the influence of human factors, the annual water resources were slightly decreased in the upper-middle reach of Huaihe River basin in 1971-2014, which might be the result of significantly increase of the annual average temperature, slightly decrease of annual precipitation, and notably decrease of annual evaporation. This study could provide a scientific basis for the management of water resources and policy-making in the upper-middle reach of Huaihe River basin.