Analysis Of Time And Space Changes And Influencing Factors Of Water Resources Ecological Surplus And Deficit In Gansu Province

Water resources are indispensable natural resources for social production and life,and the material basis for human survival.Since the reform and opening up,with the continuous development of social economy in Gansu Province,the population has been continuously increasing and people's living standards have been increasing,the demand for water resources is also growing,and the water shortage problem is more prominent due to the impact of water environment pollution and water quality decline,which limits the sustainable development of regional social economy.To clarify the spatial and temporal distribution of water resources,to master the development and utilization of water resources,and to plan and control water resources reasonably for different regions have become an urgent problem for regional sustainable development.Gansu Province is one of the most serious water shortage provinces in China.In order to promote the sustainable development and utilization of water resources in Gansu Province,based on the ecological footprint model of water resources,the ecological footprint and ecological carrying capacity of water resources in Gansu Province and 14 cities(prefectures)in 2003-2017 were calculated.On this basis,the ecological profit and loss of water resources,the ecological footprint intensity and the ecological pressure index of water resources are calculated,and the temporal and spatial change characteristics are analyzed in detail.Finally,LMDI model is used to decompose the influencing factors that cause the change of ecological profit and loss of water resources.The main conclusions are as follows:(1)From 2003 to 2017,the ecological carrying capacity of water resources in Gansu Province was far less than the ecological footprint of water resources,which led to the ecological deficit of water resources in Gansu Province during the research period,which had a great impact on the development of social economy.But generally speaking,the ecological footprint of water resources shows a slow decline trend,and the change trend of ecological deficit is basically consistent with the ecological carrying capacity,showing a fluctuating upward trend.The intensity of ecological footprint of water resources is decreasing year by year,which shows that the utilization efficiency of water resources in Gansu Province is increasing.(2)In the ecological footprint account of water resources,the production water footprint is the largest account,among which the agricultural water footprint accounts for the largest proportion,but it shows a declining trend,while the ecological water footprint accounts for a relatively low proportion,showing a rapid growth trend,indicating the rationalization of water resources utilization structure in Gansu Province.The value of ecological pressure index of water resources in Gansu Province is far greater than 1,but the overall trend is fluctuating and declining,indicating that the consumption of water resources is far greater than the supply,and the water resources are in an unsustainable use state,but the contradiction between supply and demand is alleviated.(3)The regional differences in the ecological footprint of water resources were significant,showing a decreasing trend from northwest to southeast.The intensity of the water resources ecological footprint of 14 cities(states)has shown a shrinking trend over time.The regional differences in the ecological pressure index of water resources in Gansu Province were also very obvious.The regions with larger values were Jiayuguan City and Lanzhou City,while Gannan State and Longnan City were lower.(4)The regional differences in the ecological carrying capacity of water resources were also very significant.The spatial distribution of the high-level areas and the higher-level areas was stable,and the overall trend was toward low-value areas.(5)The regional difference of ecological profit and loss of water resources is significant.The water resources do not match with the land and production layout,and the water resources ecological surplus of Gannan plateau and Longnan mountain area,which have few and scattered land resources,is large,while the water resources ecological deficit of Hexi area,which is rich in land resources,is serious(6)From the influencing factors of ecological footprint of water resources,we can see that the contribution of economic effect and technological effect is larger,while that of population effect and structural effect is smaller.In 2006,2010-2013,the structural effect promoted the ecological footprint of water resources,while in the other years,it inhibited the ecological footprint of water resources;the technological effect inhibited the ecological footprint;the economic effect and the population effect promoted the ecological footprint of water resources.This shows that the social and economic development of Gansu Province is at the cost of large consumption of water resources.Therefore,in order to ensure the sustainable development of water resources in Gansu Province,we should strengthen the construction of water conservancy facilities,actively promote and use new water-saving technology,increase the reuse rate of sewage treatment and improve the water-saving awareness of residents.