中文摘要：

为探究在气候变化和人类活动共同影响下的水沙变化问题，基于无定河流域1961—2012年的水文气象数据及水土保持措施数据，分析了流域径流泥沙的变化，并定量分解了气候变化及人类活动对流域径流泥沙影响的贡献率。结果表明：1961～2012年无定河流域径流量、输沙量均显著减小；径流量和泥沙量的突变分别发生在1986年和1978年。根据弹性系数法和敏感性分析法得出人类活动对径流减少的贡献率分别为78．75％和79．02％，气候变化的贡献率分别为21．25％和20．98％。根据累积量斜率变化率方法得出人类活动与气候变化对输沙量减少的贡献率分别为87．78％和12．22％。

英文摘要：

To explore the runoff and sediment load changes under the common impacts of climate change and human activities, based on the hydrological and meteorological data and the soil and water conservation measures data in the Wuding River basin during 1961 - 2012, we analyzed the runoff and sediment load changes in this basin, and quantitatively decomposed the contribution rate of climate change and human activities to runoff and sediment load changes. The results showed that both the runoff and the sediment load in the Wuding River basin exhibited an obvious decreasing trend from 1961 to 2012, and their sudden changing point appeared in 1986 and 1978, respectively. According to elasticity coefficient analysis and sensitivity analysis, the contribution rate of human activities to runoff reduction was 78.75% and 79.02%, respectively, and that of climate change to runoff reduction was 21.25% and 20.98%, respectively. According to the slope change rate of cumulative amount, the contribution rate of human activities and climate change to sediment load reduction was 87.78% and 12.22%, respectively.