气候变化对多年冻土区径流组成的影响分析——以长江源区为例

以多年冻土为主要下垫面的寒区流域水资源对气候变化敏感,以长江源区为例,根据数字滤波法对直门达水文站1966-2015年月径流的基流分析结果,明确了长江源区径流及其不同成分的变化规律;进一步利用格兰杰因果检验和累积斜率法分别定性和定量地分析了降水和温度对径流组成的影响.结果表明:近50年来,长江源区总径流呈现增加趋势,2...

Research on the Influence of Climate Change on the Different Runoff Components in the Permafrost Area:A Case Study of the Source Area of the Yangtze River

The water resources in the cold basin with permafrost as the main underlying surface are sensitive to climate change,taking the source area of the Yangtze River for instance,according to the base flow analysis results of runoff from Zhimengda Hydrological Station from 1966 to 2015 by the digital filter method,the variation rules of runoff and its different components in the source area of the Yangtze River are clarified.Furthermore,Granger Causality Test and Cumulative Slope Method are used to analyze the influences of precipitation and temperature on runoff.The results show that in recent 50 years,the total runoff of the Yangtze River presents an increasing trend,after the mutation point in 2004,the annual average runoff increased by 3.649 billion m3,and underground runoff and surface runoff contributed 50%respectively.The continuous increase in temperature in the last 50 years is the Granger cause of runoff variation,which is helpful to the prediction and analysis of runoff composition variation.Comparing before and after the mutation point,the surface runoff is influenced by the changes of precipitation,and also the freezing-thawing process of soil water is changed after infiltration because of the continuous increase in temperature,the contribution rates of temperature for the changes of underground runoff and surface runoff are respectively 90%and 76%,higher than that of 68%and 57%of the change of precipitation.Under the background of climate change,the continuous increase in temperature changes the precipitation form and soil water freezing-thawing process,and which is the main reason for the change in runoff composition in the permafrost area.