Analysis Of Water Resources Evolution Law And Study On Runoff Simulation In Shiyang River Basin

The spatial allocation of water resources in arid areas is a complex process involving multi-media participation,multi-level coupling,and multi-process response.Analysis and research on the temporal and spatial evolution of water resources in river basins and simulation of runoff are of great significance for achieving optimal allocation of water resources in arid areas.The Shiyang River Basin is a typical inland river basin in arid zone.Although there is a certain understanding of the evolution law of its hydrological elements and the investigation of runoff simulation,the internal mechanism of water resources in the basin is not fully and comprehensively revealed,and there are still some key problems.Can not be completely resolved.This paper takes the Shiyang River Basin as the research area,and closely follows a series of key issues in hydrological cycle elements and model parameter adjustments.Through the integration of long-term monitoring data,spatial data,socio-economic data,and hydrometeorological data,it is based on software such as SPSS and ARCGIS.Employing techniques such as cumulative slope change rate method and spatial interpolation to quantitatively reveal the evolution of hydrological elements in the study area,and use SWAT-CUP as a parameter calibration tool to achieve the optimal parameter value after multiple adjustments.Furthermore,the SWAT model is driven by CMADS as a data set to simulate and explore the coupling mechanism between land use/cover and watershed runoff in different contexts.Quantitatively reveals the hydrological cycle characteristics of the study area and the application of SWAT model in the basin.It not only provides a theoretical basis for realizing the spatial allocation of water resources in arid areas in the future,but also provides a reference for parameter values for model localization applications.The main research contents and results are as follows:1.Basic characteristics of hydrological cycle elements(1)Based on the 60-year interannual precipitation monitoring characteristics of 12 hydrological stations in the basin,the study shows that the five stations in the southwestern part of the basin are Gulangshataigou,Huangcheng Nong 4th Formation,Huangcheng Yangpozhuang,Reservoir Bashang,and Jindonggou.There is a decreasing trend in precipitation.The Huangyang Reservoir and Huangyang Water Pipe in the northeast,Zamu Huashan Village and Maozang Temple in the middle,and other seven sites,have an increasing trend in annual precipitation.It shows that from 1959 to 2019,the precipitation in the basin spatially represents the spatial evolution of the increase in the northeast region and the decrease in the southwest region.(2)The flood season of the basin and the overall annual precipitation change spatial distribution characteristics are basically the same.During the flood period,the precipitation in the northeast and southwest of the basin shows increasing and decreasing trends respectively.The increasing trend of precipitation in the northeast increases significantly,and the western imperial city of the basin The precipitation at the hydrological station and the northern Wangyang hydrological station in the flood season showed an insignificant decrease.In the non-flood season,precipitation tends to increase mainly,and the increase is significant in the western and central parts of the basin.(3)The multi-year average runoff of the Shiyang River Basin from 1959 to 2019 was13.62×108m~3/a,the standard deviation was 2.0285×108m~3/a,and the coefficient of variation(Cv)was 0.149,showing an overall downward trend,with a decline rate of 0.037 ×108m~3/a.In the 60 years of the study period,the maximum value of runoff was 18.54×108m~3/a in 2003 and the minimum value was 9.88×108m~3/a in 1991.The difference between the two is 1.88 times.(4)According to the location,number and change trend of the intersections of the UF and UB curves of annual precipitation and runoff in the Shiyang River Basin during the study period,it can be judged that the abrupt changes of interannual precipitation and interannual runoff occurred in 2017,respectively.In 2017 and 2018,the trend of change was not significant.(5)Analyzed the spatiotemporal differentiation process of groundwater depth from2013 to 2019 in the study area except for some areas.Looking at the overall situation,the depth of groundwater has been declining year by year,and the area of shallow depth has been increasing year by year.The spatial variation of groundwater depth in the basin is contrary to topographical features,which characterizes the spatial distribution pattern of deep in the southwest and shallow in the northeast.With the advancement of key governance projects for water ecological restoration by relevant government departments,the problems of serious overexploitation of groundwater and water scarcity in the basin have been alleviated to a certain extent,indicating that with the increase in environmental protection awareness,ecological governance is in the process of ecological restoration in the basin.Shows a benign role in promoting.2.In terms of parameter calibration and model simulation(1)Based on the advantages of the SWAT-CUP2019 interface,such as strong operability,multiple calibration methods,flexible calibration parameters,high efficiency and fast speed,the optimal parameter values of the Jinta River tributaries are obtained through repeated parameter adjustments.Among them,the three most sensitive runoff models are The parameters in turn are soil saturated permeability coefficient,soil effective water content,and SCS runoff curve number.(2)According to the simulation results during the rate period and the verification period,there is a good correlation between the measured runoff and the simulated runoff in the study area.(3)The meteorological database uses China's atmospheric assimilation data.The measured runoff and simulated runoff in the study area have a good correlation,which provides a guarantee for the operation of the model,and the excellent simulation results obtained from the model are also for the further study of the hydrological model of the basin Made a contribution.3.Simulation results under different land use/cover scenarios:In the study area,by setting up different land use/cover scenarios,the runoff yields under different scenarios were obtained.It can be seen that the grassland coverage is inversely proportional to the runoff,and the area of bare land is directly proportional to the runoff.As the bare land area reaches its maximum value,the simulated runoff reaches its maximum value.The simulation results can provide a theoretical basis for realizing the balanced development of ecology and economy in the study area.