Evaluation Of Green Water Resource Efficiency In Chinese Freshwater Aquaculture And Its Decoupling Analysis From Economic Growth

China is one of the countries with the most prominent conflict between water supply and demand in the world.Due to rapid economic and social development,water resources are facing increasingly serious pollution problems,which further worsens the problem of water scarcity.Solving the difficult problem of water consumption and pollution is a necessary part of promoting high-quality economic and social development.Agriculture is the major water user among the three major industries in China,with 361.24 billion cubic metres of water used in agriculture in 2020,accounting for 62.1% of total water consumption.Freshwater aquaculture is a special area of agriculture that is inseparable from water resources and plays an important role in human production and life,with population and diet structure changes,people’s demand for aquatic products is growing.As the world’s number one producer of aquatic products,China will account for more than half of the world’s total freshwater aquaculture production in 2020,which objectively requires China’s freshwater aquaculture industry to continue to play a role in securing the supply of aquatic products in the country and globally in the future.Therefore,in order to ensure the steady development of China’s freshwater aquaculture economy,there is a need to promote water conservation and pollution control in freshwater aquaculture to achieve rational water resource allocation and sustainable development of freshwater aquaculture,and improving the efficiency of green water resources in freshwater aquaculture is the key to solving this key challenge.Therefore,it is important to consider the green water efficiency of freshwater aquaculture as the subject of this paper.In this paper,theoretical analysis of green water efficiency in freshwater aquaculture is first conducted.Based on the literature review,this study establishes a framework for the analysis of green water efficiency in freshwater aquaculture and proposes a corresponding measurement model,and uses the global Super-SBM model to measure the green water efficiency of freshwater aquaculture in each province,city and district during the sample period in China;again,the Tapio Finally,the results were used to propose corresponding countermeasures to achieve green and sustainable development of freshwater aquaculture in China.In terms of the theoretical analysis of green water efficiency in freshwater aquaculture,this paper defines the concept of green water efficiency in freshwater aquaculture by combining previous research on total factor efficiency,and analyses the intrinsic effects of labour,land,capital,technology,water resources,economic output value and pollutants on green water efficiency in freshwater aquaculture,and builds the theoretical analysis framework of this paper on this basis.In terms of measuring the green water resources efficiency of the freshwater aquaculture industry,this paper constructs a model for measuring the green water resources efficiency of China’s freshwater aquaculture industry based on the global SuperSBM model,measures the green water resources efficiency of China’s freshwater aquaculture industry in 30 provinces,cities and districts from 2011 to 2020,and analyses the efficiency from three perspectives: national,local and provincial,in two dimensions:time and space.In terms of decoupling economic growth and efficiency,this paper uses the Tapio decoupling method to decouple the freshwater aquaculture economy from water resources inputs and green water resources efficiency respectively,and conducts a comparative analysis before and after the sample period.From the above empirical analysis,the following conclusions are drawn:(1)At the national level,the green water efficiency of China’s freshwater aquaculture industry is generally improving,with the 13 th Five-Year Plan period showing a more significant increase in efficiency than the 12 th Five-Year Plan period.(2)At the regional level,the average value of green water resources efficiency in freshwater aquaculture in different regions shows a decreasing trend in South China,Northeast China,North China,East China,Northwest China,Central China and Southwest China,and there are obvious differences in fluctuations within each region.(3)At the provincial level,with the exception of Beijing and Shanghai,the green water resources efficiency of freshwater aquaculture in all provinces shows a fluctuating upward trend,and the provinces with higher average efficiency values show a "V"-shaped distribution in terms of geographical space.(4)The decoupling relationship between water resources input and green water resources efficiency in the freshwater aquaculture industry and its economic growth is generally developing in a positive direction.In view of the above findings,this paper proposes the following countermeasures:(1)Optimise the layout of the freshwater aquaculture industry and develop freshwater aquaculture in accordance with local conditions.First,give full play to the characteristics of freshwater resource endowment in each region of China,and focus on building freshwater aquaculture advantageous characteristic industrial clusters,obtaining scale payoffs and enhancing green water resource efficiency in freshwater aquaculture.Second,for key aquaculture regions such as Jiangxi,Hunan and Zhejiang in China,it is recommended that economically applicable and environmentally friendly species that consume less water and discharge less water per unit be farmed according to local conditions to further optimise the structure of freshwater aquaculture species.(2)Increase capital investment and technological transformation to boost the green and high-quality development of freshwater aquaculture.First,improve the feed conversion rate with the support of science and technology to reduce the gathering of eutrophic substances.Secondly,accelerate the promotion of green farming technologies such as recycled water.Third,do a good job in treating farming tailwater,carry out environmental monitoring of farming tailwater,reduce water environment pollution at source and improve the efficiency of green water resources in freshwater aquaculture.(3)Establish and improve policies related to the freshwater aquaculture industry to ensure national food security.The first is to respond positively to the call of the Central Government’s Document No.1,to fully understand and grasp China’s basic condition of having more people and less land,and to practise the "big food concept".Secondly,we will further improve the water resource management system of the freshwater aquaculture industry in all provinces and municipalities,so that water consumption and pollution in the industry can be regulated by law and the sustainable use of water resources can be monitored from the legal level.(4)Strengthen the synergy between "green" and "economic" to achieve sustainable development of China’s freshwater aquaculture industry.(5)Make full use of both international and domestic resources,and encourage freshwater aquaculture to go global.First,improve the technical promotion system of the freshwater aquaculture industry,and promote regional cooperation and exchange in the freshwater aquaculture industry across provinces and cities.Second,actively strengthen aquaculture cooperation with countries along the "Belt and Road".In order to enhance the efficiency of green water resources in China’s freshwater aquaculture industry,to achieve green and sustainable development of China’s freshwater aquaculture industry.