中文摘要：

以渭河中下游林家村、咸阳、临潼和华县等4个典型水文站资料为例,采用滑动平均法、累积距平和线性倾向估计法分析年径流量变化趋势;采用滑动t检验,有序聚类法和Mann-Kendall法分析年径流量的突变情况。结果表明：20世纪70年代以来,渭河流域径流量呈减少趋势,各站年径流量的变化趋势相似,各水文站径流量突变点发生在70年代初和90年代初。不同水文站突变情况存在差异,林家村突变点发生在1970年和1990年,咸阳站在1970年和1990—1992年之间,临潼站在1968年和1990—1994年之间,华县站在1968年和1990年。渭河流域径流量变化是气候变化和人类活动共同作用的结果,前者主要表现为降水和潜在蒸发量的变化,后者主要体现在流域内水利工程的建设。

英文摘要：

This study analyzed the variation and abruption of runoff in the middle and lower reaches of the Weihe River,which can provide a reference for the reasonable development and utilization of water resources and promote the sustainable economic and social development. Taking four hydrological stations including Linjiacun,Xianyang,Lintong,Huaxian in the middle and lower reaches of Weihe River as an example,a moving average method,accumulative anomaly and the linear trend analysis were used to investigate the variation in the annual runoff,and the sliding t-test,a sequential clustering method and Mann Kendall method were applied to study the abruption of the annual runoff. The analysis results show that the annual runoff of the Weihe River basin has decreased since the seventies of the last century,and different hydrological stations have similar changing patterns of the annual runoff.The abruption of runoff of all hydrological stations were detected in the early 70＇s and early 90＇s of the last century.Different hydrologic stations had different abrupt points of the runoff. The abrupt points of the runoff for Linjiacun hydrological station happened in 1970 and 1990,those for Xianyang hydrological station in 1970 and during 1990—1992,for Lintong hydrological station in 1968 and during 1990—1994,and for Huaxian hydrological station in1968 and 1990. The research results reveal that the variation in annual runoff in the Weihe River was caused by both climate change and human activities. The impacts given by the climate change mainly resulted in variations of precipitation and potential evaporation in the Weihe River basin,and the impacts of human activities mainly resulted in the construction and completion of the water projects.