Research On Water Resources Allocation In The Agro-pastoral Ecotone Of The Northern Shaanxi Province Based On WAS Model

The Agro-pastoral ecotone of the Northern Shaanxi Province is located in the transition zone between the Maowusu Sandy Land and the Loess Plateau.It has obvious transitional characteristics in terms of climate,landform,vegetation and industrial economy,and it is a resource-scarce water shortage area.With the rapid development of the social economy,the demand for water resources in human society has increased rapidly.Water resources have become an important factor affecting the development of human society.Based on the dualistic water cycle theory,the allocation of water resources has solved the increasingly prominent contradiction between water supply and demand.The realization of refined water resources management is of great significance.Based on the survey and statistics of the meteorological,runoff,land use,water supply projects and other data in the Agro-pastoral ecotone of the Northern Shaanxi Province,a WAS model based on the dualistic water cycle process was constructed.The simulation results of the natural water cycle process of the model were verified by the nature runoff data from 1966 to 2010.The simulation results of the social water cycle process of the model were verified by the actual water supply data in 2015.According to the prediction results of water demand and available water volume at different incoming water frequencies in the planning year,water resources are based on the WAS model.Configuration research.The thesis has achieved the following main research results:(1)Construction and verification of WAS model in the Agro-pastoral ecotone of the Northern Shaanxi Province.According to the administrative division,water resource division and DEM elevation of the study area,17 calculation units are divided,and the water supply relationship between the calculation unit and the reservoir is determined.According to the runoff simulation results of the nature annual runoff verification models of the four hydrological stations,the average values of the correlation coefficient and Nash coefficient during the adjustment period are 0.91 and 0.67 respectively,and the average values of the correlation coefficient and Nash coefficient during the verification period are 0.76 and 0.54,the average annual runoff and 25%,50%,75%typical frequency annual runoff error rate are 3.6%,7.1%,12.4%,6.9%respectively;the model simulates the total allocation of water resources The error rate is 0.4%.The results show that the model has a good effect on the simulation of runoff process and water resources allocation.(2)Prediction of water demand and water availability under different incoming water frequencies.Using the quota method,the total water demand in the ANS at 25%,50%and 75%of incoming water frequency are 1.46 billion m3,1.86 billion m3 and 2.122 billion m3,respectively.The WAS model calculates that the local surface water resources are 1.640 billion m3,1.495 billion m3,and 1.259 billion m3 at 25%,50%,and 75%incoming water frequency,respectively,and the groundwater resources are 1.755 billion m3,and 1.534 billion m3,1.370 billion m3,respectively;according to the construction plan of the water supply project in the interlaced zone,it is predicted that in 2030,the external water supply will be 919 million m3,835 million m3,668 million m3 at 25%,50%and 75%of incoming water frequency The amount of water available for rainwater harvesting is 11.07 million m3,9.4 million m3,and 7.68 million m3,respectively.(3)Based on the WAS model,configure and analyze the water resources in the planned year.In 2030,the total water supply in the ANS at 25%,50%and 75%of incoming water frequency is 1.308 billion m3,1.614 billion m3,and 1.762 billion m3,respectively,and the total water shortage rate is 10.4%,13.6%,and 17.0%,respectively.The Canberra index was used to analyze the matching degree of water consumption and social and economic development factors.The results showed that the matching degree of water consumption with GDP,population,and cultivated land area decreased in turn,and the conversion relationship of dualistic water cycle was analyzed according to the model calculation results.