沁河流域实测径流对环境变化的定量响应分析

根据1956-2000年沁河流域降水、耗水量和入黄武陟站实测径流资料,采用趋势分析、Mann-Kendall法和滑动t检验法分析了武陟站实测径流变化的事实,辨析了影响实测径流变化的原因,并在确定基准期的基础上,建立了降水径流双累积曲线关系,分离出了由降水、人类活动中引耗水及下垫面条件变化引起的实测径流变化量.分析结果表明:沁河入黄实测径流减少趋势明显,1972年为突变年份,且降水的减少、人类活动引耗水的增加和流域煤矿开采、地下水超采和水土保持措施等综合作用致使实测径流减少.人类引耗水、气候变化及下垫面条件变化对径流的影响总量为70.6 mm,其中,引耗水致使实测径流减少为17.6 mm,贡献率均24.9％；气候变化影响量为35.6 mm,贡献率为50.4％；下垫面条件变化影响量为17.5 mm,贡献率为24.7％.

Quantitative Response of Observed Runoff in Qinhe River Watershed to Environmental Change

Based on the precipitation and water consumption data,and the runoff data observed at Wuzhi hydrological station of the Qinhe River from 1956 to 2000,the trend and abrupt change point of the observed annual runoff series were analyzed and examined using the linear trend and Mann-Kedall methods,and the sliding t-test.The reasons for changes in the observed runoff were analyzed.The linear relationship between accumulated annual precipitation and natural runoff was found for the base period 1956-1972.The amounts of the observed runoff changes caused by precipitation,water consumption and underlying surface changes were isolated.The results show that there is a distinctive decreasing tendency in the observed runoff.The abrupt change year of the annual runoff observed at Wuzhi station is 1972.The observed runoff reduction is caused by the combined effects of rainfall reduction,increase in water consumption,coal mining,and exploitation of groundwater and soil and water conservation measures.The total amount of runoff impacted by increase in water consumption,climate change,and underlying surface change is 70.6 mm,among which 17.6 mm is caused by water consumption,accounting for 24.9%,35.6 mm caused by climate change,accounting for 50.4%,and 17.5 mm caused by the change of underlying surface,accounting for 24.7%.