Research Of Water Resources Carrying Capacity Based On Uncertainty Model In Yulin City

The concept of water resources carrying capacity originates from the study of sustainable utilization of water resources,which is the concrete embodiment of sustainable development.At present,water resources carrying capacity is one of the core contents of water resources research.Yulin City is located in arid and semi-arid climate area,with dry climate and poor water resources,in order to achieve the sustainable development of economy and society,it is essential to clarify the present situation of regional water resources carrying capacity,rationally adjust the industrial structure to promote sustainable utilization of water resources.In this paper,particle swarm projection pursuit model and interval fuzzy bilevel programming model were used to study the present situation and future water resources carrying capacity of Yulin city from both qualitative and quantitative aspects.and an analyzed the influence factors of water resources utilization efficiency by DEA model and Malmquist index.The main research contents and conclusion are as follows:(1)From 2010 to 2015,the water resources carrying capacity of Yulin City was medium,but it showed a downward trend and was about to reach the limit.The carrying capacity of Yuyang District,Shenmu City and Fugu County were weak,the carrying capacity of water resources were at a low level,the carrying capacity was close to the limit,and the carrying capacity of the remaining areas were medium.By adjusting 7 variables which have a great impact on water resources carrying capacity,it's found that the effect of water resources carrying capacity improvement is very limited by tapping the potential of water saving.From a long-term perspective,in order to solve the contradiction between supply and demand of water resources in Yulin in the future,it is necessary to break the "hard restriction" of water resources by diverting water volume from Yellow River and adjust them internally,and form a unified allocation pattern so as to realize the sustainable utilization of water resources.(2)According to the uncertainty and complexity in water resource programming and management the conflicts of interests between different levels in Yulin,an interval fuzzy Bi-level programming model was established,which is constructed by combining interval planning,fuzzy programming and bilevel programming.it can deal with multiple uncertainties and effectively deal with conflicts of interest among different levels to achieve win-win situation.In addition,the use of fuzzy set theory to deal with the uncertainty of water supply can provide more decision-making options for decision makers.In the future water resources management,appropriate reference schemes can be selected in time according to the actual situation.The model was applied to analyze the optimization of industrial structure based on water carrying capacity in Yulin City.The results show that in 2025 and 2030,primary industry decrease gradually and secondary and tertiary industry increase step by step,especially the tertiary industry with the highest water use efficiency occupied an increasing proportion in the industrial structure,and the energy and chemical industry occupies the dominant position in the secondary production.In the future,the competitive advantage of the tertiary industry in Yulin City will gradually increase,and on the basis of developing the leading industry of energy and chemical industry,the tertiary industry will promote the transformation of resource-based cities and achieve high-quality economic development.Under different scenarios in 2025 and 2030,the overall agricultural,industrial and domestic water use in Yulin City is at the level of high-income countries.but the proportion of agricultural water use in some areas such as Dingbian,Jingbian,Zizhou and Mizhi is still high,and it still has space to advance.(3)The water resources utilization efficiency of Yulin City were analyzed by DEA model and Malmquist index,the results indicate that the water resources utilization relative efficiency in Yulin City showed a weak upward trend in fluctuation from 2005 to 2015,but both of them were non-DEA effective.Therefore,there is still room to improve the water resources utilization relative efficiency.The spatial distribution of water resources utilization relative efficiency was different significantly among locations,which shows that the water resources utilization relative efficiency in the central region is generally lower than that in the western and Eastern regions.Overall,the water resources utilization efficiency of Yulin City increased from 2005 to 2015.However,it should be noted that the Total Factor Productivity(TFP)value in 2015 was 0.962,which is mainly affected by the regression of technical change index.Therefore,in the future development,we should pay attention to the scientific and technological level in the process of water use,and strengthening technological improvement and innovation is the key to further improve the water resources utilization efficiency.(4)Under different scenarios in 2025 and 2030,there are differences water resources utilization efficiency in Yulin City,and the value fluctuates between 0.931 and 0.951.Compared with the historical level,it has greatly improved and is closer to the optimal level.In view of the certain gap between the relative efficiency and optimal efficiency of water resources utilization after optimization,in the future,we should continue to optimize the industrial structure according to the actual situation,further strengthen water technology improvement and innovation to improve the comprehensive efficiency of water resources utilization.