LUCC Hydrological Effects Of Mining Cities Based On SWAT Model

Industrial and Mining cities are affected by mine development and urban expansion,land use and vegetation cover changes rapidly in time and space,the ecological destruction is serious.The paper taking the Tanghe River basin of Hebi city,Henan province as the research area,this paper analyzes the characteristics of land use/cover change in the Tanghe River Basin from 1970 to 2015,constructs the SWAT distributed hydrological model,and evaluates the census data of the geographical conditions in the SWAT model hydrography.The applicability in the simulation simulated the hydrological effects under land use/cover change in the Tanghe River Basin.The main work and research conclusions are as follows:(1)Five phases of land use/cover data interpretation and classification system integration in the study area in 1970,1988,2000,2007 and 2015.According to SWAT model classification system requirements,the object-oriented image classification method was used to obtain the five-phase land use data of the study area;based on the results of the 2015 geographical national survey,the land use classification system integration method was introduced into the SWAT model.The geographical national survey data was applied to the SWAT hydrological simulation.(2)Land use/cover change analysis in the study area from 1970 to 2015 and future land use/cover simulation in the study area.Due to the impact of urban expansion and mine development,the number of land-use types in river basins has undergone major changes.The overall trend of land-use change in the study area from1970 to 2015 is consistent,but land-use changes in river basins before 2000 were slow,and accelerated significantly after 2000.From 2000 to 2015,the area of cultivated land and grassland in the Tang River Basin gradually decreased,while the area of forest land and high-density residential areas gradually increased.The annual average reduction rate of cultivated land and grassland reached 1.81%and 3.54%,respectively,and the high density of woodland.The annual increase rate of residence is 11.35%and2.01%respectively.Based on the CA-Markov model,the land use/coverage data of2007 and 2015 were used as the basic data to predict the land use and cover scenarios of the Tanghe River Basin in 2025.The simulation results show that land use types in2025 are still mainly cultivated land,grassland,forest land,high-density residential areas,low-density residential areas and water areas.Among them,the cultivated land is reduced by 28.48 km~2,and the area of high-density residential areas,forest lands,and industrial and mining land increased by 3.83km2,10.36km2,and 1.65km2,respectively.(3)SWAT Hydrological Model Construction and Application of Geographical Survey Data in SWAT Hydrological Simulation in the Study Area.Based on the DEM extracted from airborne LiDAR data,the paper collected soil,hydrology,meteorological data,and geographic national survey data in the study area.Combined with the interpretation of land use/cover data in the study area,the SWAT hydrological model applicable to the basin was established.The appraisal of the applicability of the geographical national survey data in the SWAT watershed hydrological model simulation.The simulation results show that the simulation results based on the census data rates of the periodical and verification periods(0.74,0.82)are superior to the land-use/coverage data interpretation results of the simultaneous Landsat image interpretation(0.71,0.80).The monthly runoff values simulated by the SWAT hydrological model based on the census data of geographical national conditions are in good agreement with the measured runoff values.(4)Hydrological effects under land use/cover change in the study area from 1970to 2015.Based on the calibrated SWAT hydrological model,the five scenarios of land use in 1970-2015 and the future scenarios of land use in 2025 were put in the same climate scenario.The runoff,evapotranspiration,soil leakage Volume and underground runoff,and analyzed the hydrological effects of land use change in the study area.The experimental results show that during the period of 1970-2015,both surface evapotranspiration and underground runoff in the Tanghe River Basin decreased and surface runoff increased year by year.Among them,the annual average amount of evapotranspiration and underground runoff in the basin decreased by1.48mm and 0.29mm,respectively,and the surface runoff increased by 0.76mm in the deep years.