青藏高原大通河流域径流变化归因分析OA北大核心CSTPCD

The Datong River Basin is located on the northeastern edge of the Qinghai-Tibet Plateau and is a sensi-tive and fragile ecological environment.It is of great significance to conduct research on the evolution and attri-bution of water resources in changing environments for the protection of the water ecological environment in the area and the construction of water ecocivilization.Statistical methods such as linear regression,concentration de-gree,concentration period,ordered clustering test,and wavelet analysis were used to analyze the characteristics of annual variation,seasonal distribution,periodicity,and abrupt changes in basin runoff.On the basis of the cumu-lative slope change rate method and double cumulative curve,the effects of climate factors and human activities on runoff changes were quantitatively evaluated.The results showed the following:(1)The climate in the Datong Riv-er Basin had warmed and humidified significantly in the past 60 years,with increases in average annual tempera-ture,precipitation,and potential evapotranspiration of 0.42℃·(10a)-1,8.9 mm·(10a)-1,and 5.6 mm·(10a)-1,respec-tively.The annual runoff showed a decreasing trend,with a tendency rate of 0.67×108 m3·(10a)-1.(2)The concen-tration degree and uneven coefficient of runoff showed a weak downward trend,and the increasing dry season run-off trend was evident.The seasonal distribution was more uniform,and the concentration period showed a de-layed trend,with a delay rate of 3.0 d·(10a)-1.(3)The annual runoff oscillated significantly at a scale of approxi-mately 44 years,and the mutation occurred in 1990.After the mutation,runoff decreased by 3.52×108 m3.The dis-tribution of glaciers in the basin showed a decreasing trend,whereas the vegetation cover did not show a signifi-cant change.(4)The contributions of climate and human activities to the runoff decrease in the Datong River were-17.7%and 117.7%,respectively.Precipitation was the main source of water supply in the Datong River Basin,and interbasin water transfer was the main driving factor for runoff reduction.