渭河上游径流变化特征及归因研究

分析渭河上游降水量、径流量的变化趋势和径流量的突变点,定量计算气候变化和人类活动对径流量变化的贡献,揭示渭河上游径流变化原因,为渭河流域水资源管理及开发利用提供依据。基于1961-2015年降水和径流数据,采用线性回归、Mann-Kendall检验和双累积曲线等方法分析渭河上游降水和径流演变规律。结果表明:渭河上游降水及径流的年际变化趋势均呈下降趋势,径流突变点为1970、1987、1990和1993年,根据突变点确定渭河上游径流基准期为1961-1969年;通过双累积曲线法的定量分析结果表明:人类活动是渭河上游径流减少的主要影响因素。总体上,近年来人类活动对径流的影响呈现增加趋势,2010-2015年间人类活动对径流影响的贡献率高达98. 32%。气候变化对径流变化有一定影响,尤其是,1990-1999年间气候变化对径流量影响占到22.52%。统计资料表明:在这段时间内,渭河流域发生多次极端干旱事件,导致渭河上游降水量骤减,使得气候变化对渭河上游径流变化的贡献增加。

Research on the characteristics and attribution analysis of runoff in the upstream of Weihe River Basin

The change trend of precipitation and runoff and the abrupt point of runoff in the upstream of Weihe River Basin(WRB) were analyzed. The contribution of climate change and human activities to runoff was quantitatively calculated, and the reason for the runoff variation in the upstream of WRB was revealed, which provided the basis for the management and development and utilization of water resources in the WRB. Based on the precipitation and runoff data during 1961-2015, the evolution laws of precipitation and runoff in the upstream of WRB were analyzed by using linear regression, Mann-Kendall test and double cumulative curve method. The results showed that the trends of the precipitation and runoff volume change characteristics in the upstream of WRB were decreased. The abrupt points were in 1970,1987, 1990 and 1993. According to the abrupt point, the base period for the upstream of WRB was 1961-1969. The quantitative analysis of the double cumulative curve method shows that human activities are the main factors which influence runoff reduction. On the whole, the impact of human activities on the contribution of runoff activity shows an increasing trend,the contribution rate of human activities on runoff is up to 98.32% during 2010-2015. Climate change has certain influence on runoff change, especially, the impact of climate change on runoff accounted for 22.52% during 1990-1999. The statistics show that multiple extreme drought events occurred in the WRB, which causes a drastic decrease of the precipitation in the upstream of WRB. The contribution of climate change to runoff changes in the upstream of WRB has increased.