Study On The Incoming Water Trend Of Lake And Reservoir Water Source In The Loess Plateau Under Climate Change Scenarios

In an environment of drastic global climate change,the water resources issues have become increasingly austere,stability and safety of water supply in water sources are not optimistic.Water resources are in short supply in the inland areas of northwestern my country,and the changes in the amount of water at the source of water seriously affect the safety of drinking water for the public and restrict social and economic development.Carrying out hydrological prediction and analysis research on drinking water sources can provide water management departments and local governments with a certain foresight period,and ensure that management agencies have enough time to formulate and implement relevant policies and overall arrangements to reduce the potential safety hazards of drinking water sources that may be caused by droughts and floods.This paper takes the typical small reservoir type water source site in the Loess Plateau of Northwest China—the water source area of Gaoeryuan Reservoir as the research area.The SDSM downscaling model is used to predict the future temperature and precipitation in the study area,and the SWAT hydrological model is used to simulate and analyze the inflow runoff in the future three different periods of the Gaoeryuan Reservoir’s water source.and according to the changes in the amount of storage in the future,the countermeasures for the safety of water supply at the water source are proposed.The paper mainly draws the following research conclusions:(1)The calibration period(1964-2000)and the verification period(2001-2014)in the study area simulation accuracy index determination coefficient and Nash coefficient have reached the model requirements standards,which shows that the SWAT model has good applicability in the water source area of Gaoeryuan Reservoir.(2)The SDSM model has good simulation results for the maximum temperature,minimum temperature and average temperature of the water source area of the Gaoeryuan Reservoir,while the simulation results for precipitation are average,indicating that the model has good applicability in the water source area of the Gaoeryuan Reservoir.The temperature is greatly affected by greenhouse gases and radiative forcing;the highest and average temperatures will increase in winter and summer,and the phenomenon of scorching heat and warm winter will be more obvious;the rainfall will increase in summer and autumn and floods are more likely to occur.(3)The change of annual runoff is similar to the change of precipitation in the year;the average inflow of water in the three periods under the RCP 2.6 and RCP 4.5 climate scenarios showed a decreasing trend,and under the RCP 8.5 climate scenario,it rose and then slightly decreased;the annual runoff will change greatly,and the cycle of drought and flood changes will be short;spring runoff will decrease,and autumn runoff will increase,the phenomenon of spring drought and autumn waterlogging will be more obvious.(4)The study area will be more prone to spring drought and autumn waterlogging disasters.Measures should be taken to ensure the safety of water supply in the water source area,such as establishing and improving laws and regulations,strengthening the construction of management systems,improving the intelligent monitoring and early warning system,and building an emergency guarantee system for water supply safety at the water source.