The Characteristics Of Runoff Change In The Yalong River Basin And Its Response To Climate Change

In recent years,extreme disasters have occurred frequently in my country,and global climate change has become the most severe environmental issue of this century.Climate change has an important impact on the temporal and spatial processes of the hydrological cycle in the basin.The study of future climate change and then the runoff response under climate change can provide important basis for the optimization of water resources allocation,disaster prevention and reduction of relevant departments,and it has important practical significance.Taking the Yalong River Basin as the research object,this paper firstly uses the unique data analysis advantages of ESMD to analyze the trend,cycle and abrupt characteristics of the measured rainfall runoff in the watershed,study the changes of rainfall and runoff,and obtain the impact of climate change on rainfall and runoff.Then,based on the analysis of rainfall and runoff characteristics,the HEC-HMS model in the study area was constructed,and the runoff was simulated and verified by the measured data,and the accuracy of the results was evaluated to verify the applicability of the model in the study area.Then,through downscaling,we obtain the temperature and precipitation of the three future shared socio-economic paths SSP1-2.6,SSP2-4.5,and SSP3-7.0 of CMIP6.The temperature and precipitation in the study area will show increasing trends in the future.With the radiative forcing and the future The intensity of social and economic challenges has increased,and the probability of extreme rainstorm events has increased.Finally,the results of falling water from different paths in the future are input into the HEC-HMS with a fixed rate,and the changes in the runoff of the Yalong River under the shared social economic path in the future are obtained.The results show that as the intensity of the challenge gradually increases,the runoff of the Yalong River has increased.the trend of.And with the increase in path radiative forcing and the intensity of the challenges faced,the runoff increase in each time period increases,and the runoff changes present greater uncertainty.The lag time of runoff compared with rainfall is shortened,the runoff change process is more intense,and the scheduling of reservoirs is also more severe.Is unfavorable.The research results provide a certain basis for the allocation of water resources and reduce the operational risks of the Yalong River Basin reservoir group due to climate change.