| In this paper,hailiutuhe River basin,where Dahaize Coal mine,Yingpanhao coal mine and Balasu coal mine are located,is selected as the study area,and 10 methods including digital filtering(RDF),time step method(HYSEP),sliding minimum method(UKIH)and Kalening method are applied for comparative evaluation.Using Nash coefficient and the relative error of current rabbit river basin to analyze the applicability of the base flow separation method,and choose the digital filtering method and sliding minimum method from the interannual scale,Chinese rose,dimension precision for the base flow is calculated,based on the Gis software platform,the SWAT model is established to simulate the surface water runoff and flow of dual authentication.Finally,the high-precision data output from SWAT model are input into GMS model to establish the coupling model of surface water,groundwater and mine drainage water in Hailuituhe Basin driven by multi-mine joint mining.The main achievements of this study are as follows:(1)Based on the measured runoff data of Hanjiamao hydrologic station in the Tuhe River basin,this paper uses 10 basic flow segmentation methods to segment the basic flow,evaluate the methods and parameters,and analyze the variation trend of the basic flow.The results show that digital filter F1 method has high accuracy and best effect(E>0.94MRE<0.65).The analysis results of the trend before coal mining show that the base flow in the study area shows a downward trend and an upward trend after 1997.In view of this,this study uses high-precision digital filtering method(=0.95)and sliding minimum method to carry out base flow calculation and trend analysis from different scales.(2)Compared with the baseline period from 1957 to 1972,the contribution rate of human activities was 46.2%,the contribution rate of precipitation was 53.8%,the cumulative slope decreased by 12.25%,the base flow decreased by 8.67 mm,and rainfall and human activities decreased by the base flow.From 2001 to 2017,with frequent human activities,the cumulative slope decreased by 33.58%,the contribution rate of land use/cover to baseflow was 82.24%,the contribution rate of precipitation was 17.76%,and the baseflow decreased by 10.37 mm.The influence of human activities increased obviously,and land use/cover became the main influencing factor of baseflow reduction in the Tuhe River basin.(3)Based on the data of digital elevation,Chinese soil database,land use and hydrometeorological data,the SWAT surface water model of Hailiu Tuhe river controlled by Hanjiamao hydrological station was established,and the runoff of the hydrological station was simulated in 50 years.SWAT divided the basin into 7 sub-basins and constructed land use and soil databases to generate 97 hydrological response units.Swat-cup2019 software was used for parameter calibration in the model rate periodic,model determination coefficient R2=0.78 and Nash efficiency coefficient ENS=0.79 in the model rate periodic,R2=0.81 and Nash efficiency coefficient ENS=0.80 in the validation period,and basal-diameter ratio calculated by SWAT results was 0.88,showing good simulation accuracy.(4)The groundwater of Dahaize,Yingpanhao and Balasu coal mine is a multi-layer aquifer system.In this study,the GMS model is used to divide the groundwater of Hailiu Tuhe Basin into six aquifers.Due to the simple geological structure of the mining area,the zhiluo Formation aquifer is determined as the main influencing aquifer,and the HRU data after SWAT rate is coupled with the CELL in GMS.Thus,a coupling model of mine drainage water under multi-mine combined mining is established. |
