Study On Water Resources Allocation At The North Piedmont Of Qinling Mountains Based On Ecological Water Use Guarantee

The northern foot of Qinling Mountains is located in Guanzhong area of Shaanxi Province.It's the strategic important place for the Great Development of Western China.With the intensification of water resources development and utilization in recent years,the economic and social water usage has occupied a large number of agricultural and ecological water.The research area is facing severe water shortage and water ecological deterioration.It has restricted the development of regional economy and affected the normal living environment of residents.On the basis of extensive collection of data in the research area,this paper clarifies the main problems and constraints in the development of the current situation.According to the theory of rational allocation of water resources and the method of water demand for ecological environment,this paper has forecasted the water demand for economic social development and river-lake wetland,taken advantage of Tennant method to determine the ecological basic discharge in the river.In the collar of reducing the water shortage rate of agricultural irrigation and ecological environment substantially when P=50%,increasing the compliance rate of ecological basic flow in dry season and improving the capacity of groundwater conservation,the paper has forward scientific water resources allocation scheme.And take it as the basis for ensuring the healthy and stable development of national economy,greatly improving the degree of water supply security,solving the water ecological restrictions of water resources and guaranteeing national water security.This paper draws the following conclusions:(1)According to the theory of ecological environment water demand,referencing to regional industry planning,counting measured hydrological data and water supply conditions,analyzing of evaporation,precipitation intensity,river and lake wetlands groundwater infiltration intensity,quantity of exchanged water and other factors,this paper has calculated the water requirement of ecological environment outside the river.The results show that the water requirement of the ecological environment outside the river will increase about twice as much as that of the present situation in the future.The water supply of rivers and lakes is the main water requirement,accounting for about 50% of the total water requirement.(2)Using the water resources allocation simulation model,the water resources system network of the study area is systematically generalized,and the water quantity of each link in the water resources allocation system is quantitatively analyzed.Based on water supply and use in different industries of current situation and survey data of hydrological station,this paper has calibrated the water consumption coefficient,the river load ratio.In finally,the simulation of water resources circulation system is realized.Through SPSS software,the correlation analysis between the allocation scheme of base year and the current water supply and use is carried out to verify its rationality.The results show that the river inflow coefficient is between 0.5 and 0.6,the water consumption coefficient is between 0.5 and 0.9,the correlation coefficient of water supply scheme is 0.937,and the correlation coefficient of water use scheme is 0.962.(3)According to the simulation model of water resources allocation,this paper proposed a water resources allocation scheme based on ecological water guarantee.The study shows that,under the condition of maintaining the current irrigation area and developing paddy field area moderately,the water shortage rate of agricultural irrigation could be reduced by 3 percentage points when P=50%,and sustainable economic and social development could be achieved when P=95%.(4)This study estimates the minimum ecological water requirement of River by Tennant method,an puts forward the method of analyzing regional ecological water guarantee,as well as indexes such as the amount of water entering Weihe River in dry season and compliance rate of ecological basic flow.Research indicates that,based on the consideration of natural water inflow from rivers and new water diversion projects such as Hanjiang-to-Weihe River Water Transfers and Hongyan River-to-Shitou River Water Transfers,the amount of water entering Weihe River in dry season could reach more than three times of the present situation and the compliance rate of ecological basic flow in dry season could reach more than 83% in the future.(5)Influenced by newly-built reservoirs and Large-scale water diversion project such as Hanjiang-to-Weihe River Water Transfers,in addition that the change of in river-lake wetland and the increase of effective utilization coefficient of farmland,will all have an impact on groundwater infiltration.Based on the analysis of the above changes,this paper combining qualitative analysis and quantitative calculation,estimates the groundwater conservation amount in the study area for the first time...