汉江上游径流演变趋势及影响因素分析

Analysis on runoff evolution trend of upper Hanjiang River and its influential factors

为了研究汉江上游径流演变趋势并对影响因素进行分析,根据1950～2007年汉江上游安康水文站的实测径流资料,对汉江上游径流在年际、年代、汛期(5～10月)的演变进行了分析。用径流量的累积曲线对径流变化趋势及突变进行了研究,并使用非参数M ann-Kendall法(M-K法)来检验径流的趋势变化。趋势分析表明,20世纪90年代以前,汉江上游径流呈现增加的趋势,但到了1990年后径流量锐减,进入21世纪后径流量也在减少,但减少趋势有所缓解。重点分析了1990年后汉江上游径流量锐减的主要原因,结果表明,径流减少主要原因为降水量的减少、气温的增高、下垫面的变化、社会经济耗水的增加和水资源开发利用等方面。

According to the measured runoff data of Ankang Hydrological Station in the upper Hanjiang River from 1950 to 2007,the inter-annual,decadal changes of runoff in the upper Hanjiang River are analyzed,so is the runoff changes in flood seasons（from May to October）.The variation trend of runoff and the sudden changes in upper Hanjiang River are studied using cumulative curve of runoff and the non-parametric Mann-Kendall method is adopted to verify the runoff trends.Trend analysis indicates that the runoff of upper Hanjiang River shows an increasing trend before 1990s,while there is a sharp drop after 1990,and the runoff decreases after 2000 with an eased decreasing trend.The main causes for the decrease of the runoff of upper Hanjiang River after 1990s are focused.It is shown that the main influential factors include decrease of precipitation,increase of temperature,change of underlying surface,increase of social and economic water consumption and development and utilization of water resources.