Evaluation Of Regional Water Resources Carrying Capacity Based On EFAST-cloud Model

Water is the source of life,the key of production and the basis of ecology.Water resources are the material basis for the existence of the earth's organisms and the primary condition for the sustainable development of the earth's ecological environment.Water resources carrying capacity refers to the ability of its own water resources to sustain the scale of economic and social development and maintain a good ecosystem in a certain basin or region.Scientific evaluation of water resources carrying capacity is of great significance for ensuring regional water resources security and high-quality economic and social development.Taking Henan Province as a typical research area,this paper constructed an evaluation index system of water resources carrying capacity,which included 15 indexes of water resources,economic society and ecological environment.EFAST method was introduced into the calculation of index weight,combined with the cloud model theory,an evaluation method of water resources carrying capacity based on EFAST-Cloud model was proposed,the spatial and temporal evolution characteristics of water resources carrying capacity in Henan Province were analyzed systematically.The main research results are as follows:(1)Considering the mutual feedback relationship among water resources,economic society and ecological environment system,three systems including water resources,economic society and ecological environment were constructed,the evaluation index system of regional water resources carrying capacity is composed of 15 indexes,such as water production coefficient,surface water development and utilization degree,groundwater development and utilization degree,per capita water resources,per capita water consumption,per capita industrial added value water consumption,per capita GDP water consumption,per mu water consumption of farmland irrigation,proportion of river length with good water quality,per capita COD emission,per capita ammonia nitrogen emission,per capita water and soil loss rate,per capita wetland area,eco-environmental water consumption rate and water flow barrier rate.(2)In order to reflect the coupling effect and sensitivity of water resources carrying capacity evaluation indexes and their influence on evaluation results,EFAST method was introduced into index weight calculation,combined with the cloud theory which can consider the fuzziness and randomness of the concept of uncertainty,an evaluation method of water resources carrying capacity based on EFAST-Cloud model was proposed.The evaluation results of Henan Province showed that the water resources carrying capacity from 2009 to2018 belongs to grade ?(medium)and below,and the carrying level took 2013 as the inflection point,showing a trend of first decline and then rise.Among them,the carrying capacity of water resources system was poor,the carrying capacity of economic and social system was better,the development and utilization degree of surface water,water production coefficient and per capita COD emission were more sensitive,and the per capita water resources and eco-environmental water use rate were less sensitive.Compared with the traditional TOPSIS method and entropy weight cloud model method,EFAST-Cloud model method was more sensitive to the evaluation results and can reflect the state of water resources carrying capacity more truly.(3)The water resources carrying capacity of Henan Province was evaluated at watershed scale and city scale respectively.The results showed that in the past 10 years,the water resources carrying capacity of Huaihe River Basin and Yangtze River Basin in Henan Province was better than that of Haihe River Basin and Yellow River Basin.The water resources carrying capacity of Huaihe River Basin and Yangtze River Basin was basically maintained at level ?.The water resources carrying capacity of Haihe River Basin was upgraded from level V to level IV.The water resources carrying capacity of Yellow River Basin was relatively poor and basically maintained at level V.On the city scale,Puyang City,Jiaozuo City,Zhoukou City,Shangqiu City and Jiyuan City had poor water resources carrying capacity,while the water resources carrying capacity of other cities generally remained at grade ?,with little change.