人类活动对泾河流域径流时空变化的影响

以泾河流域内14个水文站和189个雨量站的水文序列数据(1966-2005)为基础,分析了泾河流域径流的时空变化特征,并评估了人类活动对径流的影响.结果表明:径流呈明显的减少趋势,尤其是2000年后减少趋势极为显著;各子流域间径流变化存在明显的空间差异,以干流杨家坪以上及雨落坪、杨家坪至张家山区间各子流域的径流系列减少...

Impact of human activities on the spatial and temporal variation of runoff of Jinghe Basin,Northwest China

The monitored runoff and meteorological data from 1966 to 2005,collected from 14 hydrological and 189 meteorological stations,were used to analyze the temporal and spatial variability of annual runoff and precipitation,and the effect of human activities on runoff in Jinghe Basin.Within each tributary and the main stream of Jinghe,the annual precipitation has decreased less significantly,while the runoff has decreased significantly in recent decades,especially after 2000.There was a significant difference of runoff variation among the sub-basins.The most significant decrease of runoff was observed in the upstream of the main stream above Yangjiaping and the region between Yuluoping,Yangjiaping and Zhangjiashan stations,but the less significant decrease in Malianhe basin above Yuluoping.The rainfall-runoff cumulative curve method was used to detect the abrupt change of precipitation-runoff relation,and it showed that three abrupt changes had happened around 1970、1990、1998 respectively at the Yangjiaping station one abrupt change around 1998 at the Zhangjiashan station,but no abrupt change at the Yuluoping station.The spatial and temporal differences of abrupt change were mainly caused by the level of human activities.Then,the impact of human activities on runoff was assessed based on the precipitation-runoff relation in the base period of 1966-1970.The result showed that the precipitation decrease was the dominating factor that caused the runoff reduction in the three periods of 1971-1980,1981-1990 and 1991-2000,and human activities as the second factor that led to an runoff increase in the Malianhe basin or runoff decrease in other areas controlled by Yangjiaping and Zhangjiashan stations.On the contrary,the human activity became the dominant factor to the decrease of runoff in,the period of 2001-2005,with its contribution as high as rate of more than 76%,but the effect of precipitation became less significant.