Research On The Spatial Flow Pattern Of Water Resources Supply Service Based On Water Footprint

Our increasingly globalized world is characterized by cross-regional interactions of population,information,goods and ecosystem services.The protection and management of global natural resource capital requires an understanding of the complexity of the flows of ecosystem services across geographic boundaries.Water supply service is the most representative ecosystem service.The improper management of water resources in the upstream area will directly affect the water security in the downstream area.A good water environment in the downstream area also requires the joint efforts of all the cities in the basin.The study on the cross-regional compensation of ecosystem services can provide more equitable theoretical support for regional sustainable development and ecosystem services management.However,existing studies on the balance of water supply and demand have underestimated the demand for water resources in regions by ignoring the virtual water contained in various products and services.This paper takes the Weihe river basin as the research area,comprehensively quantifies the water resource demand of the research area based on the water footprint theory,and evaluates the water resource utilization status of the research area from multiple scales and angles.The spatial flow pattern based on the balance of water supply and demand and the sustainable development of water resources is quantified.The contradiction between water resources supply and demand and the spatial compensation relation of each sub-basin are evaluated quantitatively.It provides scientific basis for the basin to formulate reasonable water resources management policies,optimize industrial structure,achieve sustcainable development and establish ecological compensation mechanism.The main contents of this study arc as follows:(l)Constructing VIC model suitable for the Weihe river basin,simulating the hydrological process in each grid cell in the study area,and calculating the water resource supply in each sub-basin.(2)The total water footprint of-each region was analyzed and calculated from five aspects of agricultural water consumption,industrial water consumption?domestic water consumption.ecological water consumption and virtual water consu1ption.High resolution spatial display of water footprint is realized by GIS technology.Water resource utilization efficiency and water resource security degree in grid,city and sub-basin are calculated.(3)Based on the research framework of ecosystem service flow,the flow path is analyzed,the relationship between supply area and receive area is established,and the water resource surplus of each sub-basin is quantified.(4)The water supply service space flow pattern based on the balance of water supply and demand and the sustainable development of water resources was calculated,and the water supply relationship between supply area and beneficial area was established.(5)The ecological compensation mechanism of water supply service is established.The main conclusions of this study are as follows:(1)The total supply of water resources in the Weihe river basin is 7.338 billion m3,the supply of water resources in the Weihe river system is 3.678 billion m3,the supply of the Jinghe watershed is 1.901 billion m3,and the supply of the Beiluo watershed is 1.759 billion m3,the unit area supply of the Jinghe watershed is the lowest.On the whole,the water supply in the south of the basin is higher than that in the north.17%receive areas of the lower reaches of the basin consumed 58.64%of the water resources of the xvhole basin,and the spatial distribution of water resources supply and demand was not balanced.(2)In the situation of Water supply and demand balance,the total water supply in the Weihe river basin is 230 million mj more than the water consumption.The DX-1 was the main supply area of the Weihe watershed,the XA-2 received a total of 1.36 billion m3 of water from the upstream and reached the balance between supply and consumption.The Beiluo watershed had the largest surplus of water resources,and 135 million m3 surplus of water resources finally flowed into the Yellow River after the completion of the supply of WN-1.In the whole basin,except for TC-l?the other sub-basins all meet the balance of water resource supply and consumption,indicating that the water resource of the Weihe river basin is sufficient to meet the development needs of surrounding cities.(3)In the situation of Sustainable development of water resources,although XA-2 received a total of 1.12 billion m3 of water supply from the upstream,its water scarcity degree was still as high as 4.5.much higher than the average level of the whole basin.The Beiluo watershed has the largest water surplus,but only replenishes the WN-1.In the TC-1,there is no upstream supply under natural conditions and the water resources are under great pressure,so it is suggested to appropriately cite the water resources in the YA-3.The surplus of water resources in the Jinghe watershed was 320 million m3.and the remaining 148 million m3 of water resources flowed out of XY-3 into XA-3.It is necessary to improve residents' consciousness of water saving and reduce pollution.Afforestation outside the city to build reservoirs,to strengthen the storage of water resources.We will appropriately increase grain imports and reduce water consumption for local agriculture.The problem of water shortage in core cities can be alleviated by properly diverting water from the north slope of the Qinling mountains and the Beiluo watershed with abundant water resources.(4)In the two scenarios,XA-2 is the sub-basin that provides the most compensation,and the compensation is 3.93-10.75 billion yuan and 3.25-8.89 billion yuan respectively.In the scenario of balance between supply and demand of water resources,the sub-basin DX-1 is the main supply area of the main river system of the Weihe river basin and can collect 0.82-2.24 billion yuan of compensation from the downstream XA-2.XA-3 and WN-1.In the context of sustainable development of water resources,2.59-9.31 billion yuan can be collected from downstream TS-2,TS-3,TS-4 and XA-2.