变化环境下洮河流域径流变化归因

Attribution of Runoff Change in the Taohe River Basin Under a Changing Environment

变化环境下干旱区河川径流锐减,定量分析不同驱动要素对河川径流的影响对流域治理具有重要意义。以黄河上游洮河流域为例,采用水文模拟途径,定量分析了气候变化和人类活动对径流变化的贡献。结果表明:(1)近60年来,洮河流域径流下降趋势显著,平均线性递减率为-1.38 mm/a,实测径流系列在1986年产生突变,1986年以来实测径流量较前期减少28.5%;(2)SWAT模型可以较好地模拟洮河流域的天然径流过程,纳什效率系数NSE和决定系数R2均超过80%,相对误差RE小于7%;(3)气候变化和人类活动对径流变化的贡献率分别为58.9%和41.1%,气候变化是径流减少的主要原因,但人类活动的绝对影响有增大趋势。

The recorded runoff in arid region presented a dramatically decline trend induced by environment change.It is of significance to quantitatively analyze the influences induced by different drivers for supporting river basin management.Taking the Taohe River basin in the upper reaches of the Yellow River basin as an example,the influences of climate change and human activities on runoff change were investigated by using hydrological simulation approach.The results show that:(1)in the past 60 years,the runoff in the Taohe River basin has had a significant decline trend with an average linear decreasing rate of-1.38 mm per year;runoff series presented an abrupt change in 1986,the measured runoff after 1986 decreased by 28.5%compared with the previous mean;(2)the SWAT model performs well for simulating the natural runoff process of the Taohr River with the Nash efficiency coefficient NSE and the coefficient of determination R^2 both exceeding 80%,and the relative error RE less than 11%;(3)climate change and human activities contributed to 58.9%and 41.4%of the total runoff reduction,respectively:climate change is the main reason for runoff decrease,while the impact of human activities on runoff has an increasing trend.