Evaluation Of Water Resources Carrying Capacity Of Wuwei City Based On Combined Assignment Method And Principal Component Analysis

Humans and nature occupy a pivotal position in the entire ecosystem,and the human-water system involves many complex aspects of nature,social economy,etc,and the intensification of human-water conflicts will lead to the development of the whole system being hindered.For arid areas,water scarcity and waste is an important factor that restricts economic development.At present,Wuwei City has a serious shortage of water resources and a tight supply-demand relationship,which has become a key issue affecting the harmony between human and water and economic and social development of the region.The area is mainly dominated by agricultural cultivation,and the scarcity of water resources has restricted the agricultural and even the whole social development of the region.So,what is the current situation of water resources carrying capacity in the study area? What are the development trends? What methods and countermeasures should be taken to improve the water resources carrying capacity,etc.becomes an urgent research problem at present.Therefore,it is urgent to explore the paths and measures to achieve sustainable water resources utilization and sustainable economic and social development in the region.In order to reveal the dynamic changes of regional water resources carrying capacity and promote the sustainable use of water resources,this study evaluated and analyzed the changes of water resources carrying capacity in Wuwei from 2011 to 2020 by using the comprehensive evaluation analysis method,and the main research results are as follows:(1)Considering the water resources situation in Wuwei,with reference to the criteria for constructing the comprehensive evaluation system and the principles for selecting evaluation indicators,20 evaluation indicators are selected as the indicator layer,including per capita water resources,natural population growth rate,irrigation water consumption of farmland and water consumption rate of ecological environment.With water resources,social,economic and ecological environment subsystems as the system layer and water resources carrying capacity as the target layer,a comprehensive evaluation system is established.(2)The results show that the changes of water resources carrying capacity under both evaluation models show an increasing trend.2011～2015,the composite score under the combined assignment model is below 0.4,in the overload range,the composite score under the PCA model is negative,below the average level of water resources carrying capacity,the comprehensive evaluation of water resources carrying capacity in 2011～2015 is poor;2016～2019,the composite score under the combined assignment The comprehensive score under the PCA model is higher than the average level,and the comprehensive evaluation of the water resources carrying capacity in2016-2019 is medium level;in 2020,the comprehensive score under the combined weighting model is higher than 0.8,which is a bearable state,and the comprehensive score under the PCA model is higher than 3.16,which is a better level,and the comprehensive evaluation of the water resources carrying capacity in 2020 is better.The comprehensive evaluation of the carrying capacity of water resources in 2020 is good.The two evaluation results are considered that the combined assignment model is more suitable for evaluating the carrying capacity of water resources in Wuwei,and can provide reference for similar studies.(3)Using the barrier degree model to analyze the key barrier factors,it shows that the key factors of water resources carrying capacity in Wuwei include per capita water resources,per mu water resources,water production modulus,water supply modulus,per capita water supply,annual runoff coefficient,population density,natural population growth rate,irrigation water use rate of farmland,water use rate of10,000 yuan of industrial value added,and water use rate of ecological environment.The system level barrier degree ranking is water resources system(392.01%)>ecosystem(271.54%)> social system(165.91%)> economic system(126.57%).Based on the results of the barrier degree model analysis,relevant countermeasures from improving population literacy to building a firm ecological barrier are proposed.