Research On Spatial-temporal Evolution And Driving Factors Of Water Resources Green Efficiency In Northwest China

The northwest China accounts for 35.9%of the national land area,but the water resources only account for 5.7%,and the water yield per unit area is only a quarter of the national average,forming an extremely fragile ecological environment foundation in this region.The extensive use of water and the unreasonable structure of water use in the northwest region,as well as the persistence,inefficiency,and lag of water resource development and utilization models,have led to low and increasingly poor water resource utilization efficiency.The unit output of aquatic products is far below the national average level.In addition,the excessive use of fertilizers and the indiscriminate discharge of industrial wastewater have caused serious pollution of the water environment and serious degradation of the water ecology.The contradiction between supply and demand of water resources and low green efficiency have become important bottlenecks that constrain the construction of water ecological civilization in the northwest region.Therefore,based on the analysis of the current situation of water resource supply and demand in the northwest region,this article constructs a multidimensional indicator system for water resource green efficiency based on input,expected,and unexpected output,measures the green efficiency of water resources in various regions and industries in the northwest,identifies the dynamic evolution characteristics,spatial autocorrelation,and spatial convergence of water resource green efficiency in different industries,and analyzes the spatial spillover effects and driving factors of water resource green efficiency.Finally,on this basis,explore the construction of a green efficiency optimization path for water resources based on the "macro meso micro" trinity.The research findings are as follows:(1)The imbalance between supply and demand of water resources in the northwest region is prominent,and shows a continuous deteriorating dynamic trend and spatial differences.In terms of total water supply,even with water supply rates of up to 40%and 90%respectively,and recycled water rates,by 2035,except for Qinghai,which has developed water systems and a sparse population,the average annual water shortage in Shaanxi,Gansu,Ningxia,Xinjiang and other places is between 36.667 to 44.368 billion cubic meters,showing an increasing trend year by year.In space,the degree of imbalance between supply and demand of water resources in the northwest regions is different.The scarcity of water resources in Shaanxi has deteriorated from moderate water shortage to severe water shortage.The degree of water scarcity in Gansu and Xinjiang is extremely water shortage and continues to deteriorate;although the water shortage rate in Qinghai is negative,the gap between supply and demand is gradually narrowing.The water shortage rate in Ningxia is decreasing year by year,but water resources are also extremely scarce.The problems of total structure,allocation efficiency,science and technology and management system are the common problems of water resources supply and demand imbalance in Northwest China.(2)The green efficiency of water resources in Northwest China shows obvious industry heterogeneity and spatial heterogeneity.From the perspective of industry heterogeneity,the average value and annual average growth rate of green efficiency of domestic service water are the highest,while the average value and annual average growth rate of green efficiency of agricultural water,industrial water and ecological water are relatively low,and show a ’U’ type change trend of decreasing first and then increasing.From the perspective of spatial heterogeneity,the areas with higher green efficiency of agricultural water use are mainly concentrated in northern Xinjiang,Gansu and Shaanxi,and there is a trend of gradual strengthening over time.The areas with high green efficiency of industrial water are mainly concentrated in the eastern part of the northwest region,and have the trend of strengthening to the region.The areas with higher green efficiency of domestic service water are mainly concentrated in northern and eastern Xinjiang and some southern regions,and gradually shift to the Hexi Corridor and southern Gansu and southern Shaanxi.The green efficiency of ecological water use is relatively concentrated,and has the trend of gradually strengthening to the Hexi Corridor and some eastern regions of the northwest region.(3)The green efficiency of agricultural water,industrial water,domestic service water and ecological water in Northwest China will converge to their respective steady-state growth paths at different rates.The convergence rate of industrial water green efficiency in Northwest China is the highest,about 3.80,but it will gradually decrease with time.The convergence rates of green efficiency of agricultural water,domestic service water and ecological water are relatively low,which are about 3.30,3.25 and 3.21 respectively,and show a gradual upward trend.The convergence and convergence rate of green efficiency of agricultural water,industrial water,domestic service water and ecological water are not only related to the level of economic development,population size,industrial structure and government expenditure,but also affected by the spatial spillover effect of green efficiency of water resources in adjacent or adjacent areas(except the green efficiency of domestic service water).(4)The green efficiency of water resources in different industries in Northwest China has a significant positive spatial spillover effect.In addition to ecological water,the green efficiency of agricultural water,industrial water and domestic service water all show obvious positive spatial spillover effect,which means that the green efficiency of agricultural water,industrial water and domestic service water in the region will also be affected by the green efficiency of agricultural water,industrial water and domestic service water in adjacent or adjacent areas.That is to say,the green efficiency of agricultural water,industrial water and domestic service water in the adjacent or adjacent areas of geospatial space shows the spatial characteristics of ’ prosperity and decline ’.(5)The driving factors of water green efficiency in different industries in Northwest China are different.In addition to the influence of various driving factors in the region,it is also affected by various driving factors in adjacent or adjacent areas.The main driving factors of agricultural water green efficiency are economic development level,industrial structure rationalization,population density,human capital level,government fiscal expenditure and scientific and technological innovation ability.The main driving factors of industrial water green efficiency are economic development level,industrial structure rationalization,human capital level,government fiscal expenditure and scientific and technological innovation ability.The main driving factors of green efficiency of domestic service water are population density,urbanization level,human capital level and technological innovation ability.The main driving factors of green efficiency of ecological water use are economic development level,industrial structure rationalization,human capital level,government fiscal expenditure and scientific and technological innovation ability.(6)The optimization of green efficiency of water resources in Northwest China needs to work together from three dimensions:macro(institutional mechanism optimization),meso(structural adjustment optimization)and micro(water-saving technology innovation),and explore the construction of ’trinity’ green efficiency optimization path of water resources.Among them,to promote the innovation of the system and mechanism of green efficiency optimization of water resources in Northwest China,it is necessary to strengthen the precise subsidy mechanism of comprehensive reform of agricultural water price,promote the new model of urban-rural integration of water resources management,and establish a unified cross-regional coordination mechanism.To promote the structural adjustment and optimization of the green efficiency optimization of water resources in Northwest China,it is necessary to explore the construction of an economic structure system suitable for the green and efficient utilization of water resources,adjust the agricultural planting structure,reduce the planting scale of high-water-consuming crops,adjust the internal layout of industry,and vigorously develop high-tech green industry.In order to promote the water-saving technology innovation of green efficiency optimization of water resources in Northwest China,it is necessary to strengthen the promotion of irrigation water-saving technology,increase the research and development of industrial water-saving technology,and vigorously promote the construction of water-saving equipment and water-saving infrastructure.