| The study of the influence of climate change on the runoff in the upstream of hydropower station can predict the amount of water coming from hydropower station in advance,which is of great significance for water resource allocation and power generation benefit analysis of hydropower station.Based on the hierarchical weihe river basin as the study area,wei jia fort hydropower station as the research object,based on the Delta method and CMIP5 data,using the SWAT model forecast,meteorological and hydrological situation analysis in the study area under different climate scenarios,in combination with wei jia fort hydropower station operation,will predict the runoff as a reference,analysis the power generation benefit of hydropower station under different climate environment.The main conclusions of this paper are as follows:(1)The runoff features of two major hydrological stations in the study area(1960-2000)were analyzed by Kendall rank test,mann-kendall method,wavelet analysis and other methods,so as to obtain the runoff features of the entire study area in the past 40 years.According to the analysis in this paper,the flood season of runoff is concentrated in July,August,September and October,and the dry season is in December,January and February every year.In the late 1980 s,the runoff sequence was mutated,and the runoff showed a significant decreasing trend.On the whole,water resources in the study area showed a tendency of tension.(2)Using DEM map,soil raster data and land use raster data map of the study area,as well as meteorological data of four sites,to build a local database of SWAT model in the middle and upper reaches of weihe river.The applicability of the SWAT model in the study area was judged by model parameter calibration and site runoff process simulation.According to the simulation results,the model simulates runoff well with measured runoff,and the Nash coefficient ENS of the verification period and the rate at regular intervals are all above 0.7,the coefficient R2 is determined to be above 0.8,and the relative error Re is also within 20%.In conclusion,it is proved that the SWAT model has good applicability in the research area.(3)BCC-CSM1.1 model data in CMIP5 data under global climate model(GCMs)were processed based on Delta method,and the future rainfall,maximum temperature and minimum temperature conditions of the study area under different climate scenarios(RCP2.6,RCP4.5,and RCP8.5)were analyzed.Compared with the base period,the temperature of the four meteorological stations in the study area shows an increasing trend in the next 40 years,and the temperature increases with the increase of the typical concentration.The trend of rainfall is also increasing in the future,but with the typicalconcentration of greenhouse gases,the increase of rainfall tends to decrease.(4)The SWAT model was driven by climate data in future different climate scenarios to estimate the runoff process of weijiapu.The research results showed that the average annual runoff of the site in the next 40 years was 2.431 billion m3,2.337 billion m3 and2.284 billion m3 respectively in three climate scenarios,which decreased by 16.78%,20.01% and 21.81% compared with the base period.In the next 40 years,the runoff shows a decreasing trend.The monthly runoff decreased in summer and increased in winter.(5)The water amount of the hydropower station under three climatic scenarios is obtained through estimation,and the power generation benefit of the hydropower station is analyzed.Under the scenes of RCP2.6,RCP4.5 and RCP8.5,the average annual power generation of the power station is respectively 71 million kW·h,68 million kW·h and 67 million kW · h.As a result of the sudden change of runoff flow,the power generation benefit of hydropower station decreased sharply after 2041. |
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