Study On Runoff Response Of The Yalong River Basin Under Future Climate Scenarios

Climate change has an important impact on the hydrological cycle of the basin.The Yalong River basin is an important hydropower energy base in China.The runoff response caused by future climate change has far-reaching impact on the development and management of hydropower energy in the basin.Therefore,the study of runoff under climate change The response process is important.In this paper,we use the downscaling technology to generate precipitation and temperature in different scenarios in the future,and further couple the hydrological model to obtain the future runoff trends in the Yalong River Basin.The main achievements include:(1)The application of distributed hydrological model in the Yalong River Basin was carried out,and the SWAT distributed hydrological model of the Yalong River basin was established on the time scale of the Yalong River.The results show that both models can be in the Yalong River Basin.With strong applicability,the NSE of each site on the daily scale is 0.78 and above,and the NSE of each site on the monthly scale is above 0.8 and above,and the spatial applicability is verified.In the space verification,the two time scales of the two stations are 0.8 and 0.91 and above;(2)The application of SDSM and ASD statistical downscaling models in the Yalong River Basin was carried out,and two statistical downscaling models of rainfall and temperature in the Yalong River Basin were established.The results show that both models can be elegant.The temperature of the Lancang River Basin is simulated and the applicability is strong.The interpretation variance of the two models for precipitation simulation is also within a reasonable range.Comparing the monthly average of the two models in the baseline period with the measured values,the applicability of the ASD model is slightly better.In the SDSM model,both models showed that the rainfall in July was greater than the measured value.The two models are simulated to simulate the SWAT model of rainfall and temperature input rate.The results show that the simulation results are similar to the measured meteorological input,which further verifies the correctness of the simulation results of the downscaling model;(3)The future rainfall and temperature prediction of the Yalong River basin based on SDSM and ASD statistical downscaling models were carried out,and the rainfall and temperature prediction models for the future of the Yalong River Basin were established in the next 2021-2100 years.The results show that SDSM in the future period.The model and ASD models predicted the lowest temperature trends in the three climate scenarios-0.005~-0.012°C/10 a and 0.004~-0.014°C/10 a,respectively,and the highest temperature trends were-0.005~-0.012°C/10 a and 0.004 ~-0.014 °C/10 a,the rainfall trend is-2.6~-20.9mm/10 a and 1.3~-21mm/10 a respectively;(4)The future runoff response study of the Yalong River Basin was carried out,and the downscaling-hydrological coupling model was established to obtain the runoff process under the various scenarios in the future.The results showed that the runoff trends of the two models were directly related to rainfall,SDSM model.The simulated runoff is larger than the ASD model.The maximum monthly runoff increase is the SDSM model in July of the 2030 S period in the RCP4.5 scenario.The largest month of runoff reduction is the SDSM model in the RCP8.5 scenario in the 2090 S period.