Analysis Of Water Resource Availability In Yanghe River Basin Based On SWAT Model

In recent years,with the rapid development of social economy,the demand for water resources in the region continues to rise,and the shortage of water resources is more obvious.In the future,the contradiction between the supply and demand of water resources in the region will be further intensified.How to reasonably and effectively develop regional water resources and solve local water shortage problems,so as to ensure the sustainable development of social economy and ecological environment is a difficult problem to be solved.Taking Yanghe river basin as the research object,this paper analyzes the changes of regional water resources availability under typical hydrological years,aiming at the prominent contradiction between supply and demand and the unreasonable development and utilization of water resources in the basin.In Yanghe river basin water resources development and utilization of the status quo,on the basis of the SWAT model is used to analyse the Yanghe watershed runoff simulation and to explore its applicability,and quantitative analysis of different hydrological changes in the basin water resources availability,can for the local optimal allocation of water resources reasonable development and provide technical support,for solving the problem of water shortage of local local has a certain theoretical basis and application value.The main research results of this paper are as follows:(1)The average annual water consumption in Yanghe river basin is 4.78 million m~3,among which the average annual water consumption on the surface is 1.40 million m~3,accounting for 29.3%of the total water consumption.The average annual underground water consumption was 3.38 million m~3,accounting for 70.7%of the total,and the annual water consumption remained basically unchanged.The main water consumption in the basin is for agriculture and industry,accounting for 62%and 18%of the total water consumption respectively,among which 51%and 22%are groundwater.By comparing the water consumption of Yanghe river basin with that of Zhangjiakou city,it is found that the average annual water consumption in the basin accounts for 62%of the average annual water consumption of Zhangjiakou city.(2)The selection for model preheating period 2008-2010,2011-2013 for the model rate,on a regular basis for model validation period,from 2014 to 2015,according to the results of Yanghe river basin facies,Chaigoubao(east)and Chaigoubao(south)facies,two hydrologic rate regular correlation coefficient R~2of 0.85 and 0.66 respectively,the efficiency coefficient of NS are 0.81 and 0.64 respectively,validation period R~2of 0.86and 0.60 respectively,NS were 0.79 and 0.58,various evaluation indexes can meet the accuracy requirement.By spreading the determined parameters to the whole basin,the average annual runoff of the total water outlet in the natural state(without considering the water consumption in the basin)is 2.34 million m~3.On this basis,the average annual surface water use within the basin is 1.40 million m~3,which is roughly equivalent to the measured annual runoff of no.8 bridge section of 0.87 million m~3,indicating that the SWAT model has a good applicability in Yanghe river basin.(3)The simulation results under different hydrological years show that the annual yield of high water is 3.43 million m~3,that of normal water is 2.25 million m~3,and that of dry water is 1.53 million m~3.Taking a plain water year as an example,the total water yield of yanghe river basin is 2.25 million m~3,the water demand of river ecological environment is 1.64 million m~3,and the amount of water resources difficult to use is 0,so the usable amount of surface water resources is 0.61 million m~3.For each control section,the surface water resources of Zuowei and Xiangshuipu can meet the ecological environmental water demand of the river in their sections,and the available surface water resources are 0.93 million m~3and 0.26 million m~3respectively.The surface water resources of Jimingyi and no.8 bridge cannot meet the ecological environmental water demand of the river in their sections,and the available surface water resources are negative,which are 0.54 million m~3and 0.03 million m~3respectively.Therefore,the surface water resources can be utilized in the two areas above and above the Zouwei and the Zouwei-Xiangshuipu by increasing the discharge of the reservoir and building ditchways,so as to meet the water demand of the ecological environment of the river in the two areas of the Xiangshuipu-Jimingyi and the Jimingyi-no.8 bridge.(4)According to the simulation results of the hydrological cycle of SWAT model,when the water in the basin is not considered in the natural state,the input amount of shallow groundwater is mainly rainfall infiltration recharge,which is 7.79 mm/yr.The output is 26.12 mm/yr,including the amount of evaporation 23.7 mm/yr,the amount of replenishment channel 2.03 mm/yr,and the amount of replenishment deep groundwater0.39 mm/yr.It can be seen that the annual output of shallow groundwater is as much as18.33 mm/yr larger than the input,which leads to the decline of the groundwater level year by year.In this paper,based on the local government's plan for the exploitable amount of groundwater,the exploitable amount of groundwater resources in the inland basin is 4.55 million m~3.(5)Considering the limits of surface water resource availability and groundwater resource availability under different hydrological years,in a year of abundant water,the water resource availability in Yanghe river basin is 6.34 million m~3.The water resource availability is greater than the water consumption,and the surplus is 1.56 million m~3,which can meet the regional water demand.In a plain water year,the exploitable amount of water resources in Yanghe river basin is 5.16 million m~3.The exploitable amount of water resources is basically the same as the water consumption,and the surplus amount is only 0.38 million m~3.When the development of social economy in the basin has more water demands,the exploitable amount of water resources in the region cannot meet the requirements.In dry years,the available water resources in Yanghe river basin are 4.44 million m~3,and the available water resources are smaller than the water consumption,with a water shortage of 0.34 million m~3.Therefore,the water demand in the basin can only be met by carrying out water transfer in the outer basin and planning and utilization of reclaimed water.