Study On Variations Of Runoff And Its Components In Three Source Streams Of Tarim River

Global warming has a far-reaching impact on the hydrological cycle process and the planning and utilization of water resources in arid basins.The headstream of the Tarim River is close to the alpine mountainous area.The glacier snowmelt runoff is the main component of its runoff,and the mountain mouth runoff is the main source of water for the middle and lower reaches.Climate warming has intensified the water cycle process,making climate change in alpine and arid basins more complicated,and intensifying the uncertainty of hydrology and water resources in the basin.Therefore,the quantitative analysis of the evolution of the runoff and its components of the three source streams of the Tarim River under the conditions of climate change is of great significance for promoting the rational allocation and efficient use of water resources in arid areas,the development of ecological civilization,and the social economy.This article is based on the SPHY model,and on the basis of preparing a model-driven database,the three source streams of the Tarim River,the Yeerqiang River,the Hotan River(Karakhashe River and Yulong Kashi River),and Aksu River(Kumalak River and Toshi Dry River)from 1981 to 2010 The runoff from the mountain vent was simulated,and the contribution of four runoff components of base flow,glacier runoff,rainfall runoff and snowmelt runoff to the total runoff was quantitatively calculated,and the composition and change characteristics of runoff were analyzed.The downscaling data-driven model is used to estimate the runoff and its components in the study area from 2011 to 2035.Based on the analysis of the inter-annual and intra-annual variation characteristics of the future temperature and precipitation in the basin,the future runoff in the three source basins of the Tarim River is discussed.The law of evolution and the response to climate change.Good applicability has been achieved,and the main conclusions are as follows:(1)From 1981 to 2010,glacier runoff and snowmelt runoff in the Yarkand River,Karakash River,Yulongkashi River and Kumarak River were the main components of its runoff,and the annual average proportions were as high as 81.9%,71%,79.9%and 78%,respectively.In the Tosh Wadi,rainfall and glacier runoff are the main components of its runoff,with an average of 65%for many years.The annual concentration of each runoff component is mainly from April to September.Affected by temperature and precipitation,the glacier Runoff showed an increasing trend in the Yeerqiang River,Karakash River,Yulongkashi River and Kumarak River,and a decreasing trend in the Toshi Dry River;snowmelt runoff all showed an increasing trend;Rainfall Runoff in the Yeerqiang River,Kumarak and Toshigan The rivers showed an increasing trend,and the Karakash River and the Yulong Kashi River showed a decreasing trend.(2)From 2011 to 2035,under the global climate change scenario,the basin temperature and precipitation showed an increasing trend compared with 1981-2010.Among them,the annual average temperature increased by 0.73?-1.83?,and the multi-year average rainfall increased by 4.15%-32.19%,which will lead to certain changes in future runoff;the Yerqiang River,Karakash River and Kumarak River will have the largest increase in annual average runoff under the ACC4.5 scenario,which is 50.00%,41.67%and 12.73%respectively.Yulong Kashi River Under the BCC8.5 scenario,the increase is the largest at 52.17%.Under the ACC8.5 scenario,the increase is the largest at 53.33%.The future runoff changes within the year will vary with the increase in temperature,showing obvious differences in the flood season.The difference in non-flood season is not significant.(3)From 2011 to 2035,under different climate scenarios,the future runoff components will not change much from 1981-2010;the multi-year average proportion of base flow does not decrease significantly;the proportion of snowmelt runoff shows an increasing trend and fluctuates between years Increasing state;the proportions of glaciers and rainfall runoff in the Yarkand River,Karakash River,Yulongkashi River and Kumarak River have shown increasing and decreasing trends,respectively.The inter-annual fluctuations are in a state of increasing and decreasing fluctuations,while it is in Tosh The dry river showed a state of decrease and increase,respectively.The inter-annual trends showed an increase first and then a decrease and an increase in fluctuations,and the greater the temperature increase,the more obvious the degree of change;the future rainfall runoff in the basin showed a consistent change trend with the rainfall.Taken together,temperature is the main factor that affects glacier snowmelt runoff,and whether rainfall runoff increases depends mainly on how rainfall changes in the future.