中文摘要：

黄河中游产流量在过去几十年发生了明显减小的变化趋势,鉴于迄今有关气候及人类活动对该区产流量减小的影响比重仍存争议,本研究利用累积距平方法分析了研究区近60年来的产流量变化趋势,识别出1971年和1985年两个拐点年份,利用累积量斜率变化率分析方法（SCRCQ）估算了降水量和人类活动在产流量变化中的贡献率。与基准时期1950-1970年（TA）相比,在不考虑蒸散量影响的情况下,降水量和人类活动对黄河中游区间产流量变化的贡献率在1971-1985年（TB）分别为25.94%和74.06%,在1986-2009年（TC）分别为25.13%和74.87%;如果考虑蒸散量的影响,则人类活动的贡献率在TB和TC时期分别增大到91.74%和93.41%。显然,人类活动是该区间地表产流量减小的最重要影响因素。人类活动对黄河中游区间产流量变化的主要影响方式是拦蓄滞留,这些拦蓄滞留的水量大多数最终通过蒸散作用而从地表径流循环进入大气循环,即人类活动改变了部分水循环的途径。

英文摘要：

The runoff yield in the middle Yellow River Basin has shown an evident decreasing trend during the last decades. The proportion of contributions of climate and human activities to the runoff yield change in the study area is still in dispute. In this paper, the variation trend of the annual runoff yield in the study area during the last 60 years were studied using the method of cumulative anomaly, and two turning years, 1971 and 1985, were identified. The method of slope change ratio of cumulative quantity （SCRCQ） was adopted in estimation of the contributions of climate change and human activities to the runoff yield change in the study area. The results showed that without regard to the influence of evapotranspiration in the area the contributions of climate change and human activities to the runoff yield change were 25.94% and 74.06% in the period 1971-1985 （TB）, and 25.13% and 74.87% in the period 1986-2009 （Tc）, respectively, compared with the base period 1950-1970 （TA）. Under the conditions of regarding to the influence of evapotranspiration in the area, the contributions of human activities to the runoff yield change were 91.74% and 93.41%, respectively during the time periods of TB and To. Obviously, the human activities were the dominant factor influencing the runoff yield changes in the study area. The main modes of human activities influencing the runoff yield change in the middle Yellow River Basin were interception of runoff by a series of check-dams and other soil and water conservation measures. The intercepted water was mostly participated in the atmospheric cycle by evapotranspiration, indicating that human activities altered the cycle route of part of water in the middle Yellow River Basin.