Runoff Simulation In The Biliu River Basin And Its Response To Future Climate Change

It is of great significance to study the change of the future meteorological elements and study the response of runoff to the future meteorological elements.It can provide theoretical basis for scientific planning of water resources allocation,reservoir scheduling,reservoir water regulation and ecological protection for relevant departments.Firstly,the SWAT distributed hydrological model is applied to the basin,and the model localization is used to simulate the runoff in the historical period,and the SUFI-2 algorithm in SWAT-CUP is used to analyze the parameter sensitivity analysis and the simulation results of the model.Then,in the Bi Liuhe river basin,the model is analyzed and evaluated.The SDSM model of statistical downscaling method is established.By using the measured meteorological data and the NCEP reanalysis data,the statistical empirical relation rate between the prediction factor and the forecast factor is established,and the Nash efficiency coefficient and the relative error are used to analyze the model effect.Then,the two scenarios of the CanESM2 model are RCP4.5.And the future meteorological elements under RCP8.5,including temperature and precipitation,are simulated,and finally,the future scenario results are input into the SWAT model,and the response of the Biliu River in the future climate change is obtained.The conclusions of this study are as follows:?1?The SWAT distributed hydrological model shows good applicability in the runoff simulation of the Biliu river basin.Using SWAT-CUP to analyze the sensitivity of parameters,the sensitivity of the distributed hydrological model is as follows:CN₂,SOL_AWS,GW_REVAP,GW_REVAP,GWQM and so on.?2?The simulated values of the binliu river station are in good agreement with the observed values,and the flow process is well fitted.The rate of regular and verification period R² are 0.92,0.92,and 0.92,respectively,0.91 and 0.92,respectively,under the control of 5%,respectively,and the whole tribe in a smaller uncertain interval?95PPU?,but the simulation effect on the peak value The simulated value is generally less than the measured value,which may be due to the influence of snowmelt.?3?The statistical relation between the forecast factors and the prediction variables established in the region by the statistical downscaling model SDSM,the result of the rate determination and the verification period shows that the model can be used to simulate the scale of the large-scale meteorological factors.And the simulation results of the reference period show that the simulation effect of temperature is better than the effect of precipitation simulation.The simulation Nash efficiency coefficient of the temperature is almost 0.95,and the correlation coefficient is about 0.95.?4?Input two scenarios of CanESM2 mode RCP4.5 and RCP8.5,and get the future climate scenarios of watershed by downscaling model.The results showed that under the two scenarios of RCP4.5 and RCP8.5,the lowest temperature and the highest temperature were all rising,and the precipitation increased in the two period.Compared with the average annual precipitation in the two period and the baseline period,the average precipitation increased in 2046-2065 and 2081-2100years.?5?The meteorological information?mainly including precipitation,maximum temperature and minimum temperature?in different scenarios?including precipitation,maximum temperature and minimum temperature?under different scenarios?mainly including precipitation,maximum temperature and minimum temperature?is put into the SWAT model which has been established,and the runoff in the two period of the River Basin is predicted.The results show that in the next 2046-2065 year period,the two scenarios are all less than that of the base period.The annual runoff of RCP4.5 decreases by 4.2m3/s,and the annual average runoff of RCP8.5 decreases by 2.6 m3/s.In the 2081-2010 year period,the average value of the two scenarios is lower than the year average of the baseline period and the annual average of RCP4.5.The runoff decreased by2.6 m3/s fand than the benchmark period,2.1 RCP8.5 m3/s fand increased the ratio of the reference period.