Coupling Diagnosis Analysis Of Water Resources Carrying Capacity And Utilization Efficiency In The Yellow River Basin

Water resources are important ecological resources.Improving the carrying capacity and utilization efficiency of water resources is the key to achieving ecological protection and high-quality development in the Yellow River basin.This paper takes 77 cities in the Yellow River basin from 2010 to 2020 as the research object,measures and analyzes the water resources carrying capacity and utilization efficiency of different cities,and carries out coupling diagnosis.The main research contents include the following three parts:1.Measurement and analysis of water resources carrying capacity in the Yellow River Basin.This paper constructed the evaluation index system of water resources carrying capacity from three criteria levels of water resources endowment,economic society and ecological environment,determined the combined weight based on CRITIC method and principal component method,measured the water resources carrying capacity level of77 cities in the Yellow River basin through TOPSIS model,and analyzed its space-time evolution.The results showed that:(1)The overall water resources carrying capacity of the Yellow River basin showed a steady and slow rise during the sample period,and the water resources carrying capacity index gradually increased from 0.4921 in 2010 to0.5335 in 2020;(2)The carrying capacity of the water resource endowment subsystem showed a trend of first decreasing and then fluctuating and rising,the carrying capacity of the economic and social subsystem showed a trend of substantial increase,and the carrying capacity of the ecological environment subsystem showed a slow upward trend in general;(3)The water resources carrying capacity of the Yellow River basin presented a "low-high-low-high" spatial pattern from west to east,and with the passage of time,the water resources carrying capacity of the cities in the upper and middle reaches had increased significantly,and the spatial distribution difference has decreased.2.Measurement and analysis of water resources utilization efficiency in the Yellow River Basin.In this paper,three input factors of resources,capital and labor were selected,and economic benefits and environmental costs were taken into account to construct an input-output index system of water resources use efficiency.The ultra-efficiency EBM model containing unexpected output was used to measure and decompose the water resources use efficiency of cities in the Yellow River Basin,and its spatiotemporal evolution was analyzed.The results showed that:(1)During the sample period,the water resources use efficiency in the Yellow River Basin increased from 0.6806 in 2010 to 0.7082 in 2020,with an annual mean of 0.6996,which did not reach the effective state.(2)The spatial pattern of water resources utilization efficiency in the Yellow River basin presented a "low-high-high-high" distribution from west to east.High-efficiency cities were mainly distributed in Shandong Province and Inner Mongolia Autonomous Region.The water resources utilization efficiency of upstream cities was relatively low,and the inefficient areas were mainly concentrated in Gansu Province and Ningxia Hui Autonomous Region.(3)The difference in water resource utilization efficiency among cities in the Yellow River basin was caused by the difference in pure technical efficiency,and its effect intensity was still strengthening.3.Coupling diagnosis of water resources carrying capacity and utilization efficiency in the Yellow River Basin.Based on the measurement results of water resources carrying capacity and utilization efficiency,the coupling coordination status and health level of water resources carrying capacity and utilization efficiency in the Yellow River basin were diagnosed and analyzed by means of bearing capacity product and coupling diagnosis method.At the same time,the spatial differences and distribution characteristics of water resources carrying capacity and utilization efficiency in the Yellow River basin are analyzed by combining with the Thiel index and GIS distribution map.The results showed that:(1)The water resources carrying capacity of the Yellow River basin showed a trend of increasing year by year during the study period,from 0.3491 in 2010 to 0.3932 in 2020,with an average annual value of 0.3727.The coupling and coordination level of water resources carrying capacity and utilization efficiency in the lower reaches was the highest,and the integration state was the best.The overall difference of the water resources carrying capacity in the Yellow River basin had shown a trend of narrowing.The overall difference was mainly caused by the intra-group difference,and the internal difference in the upstream region had the greatest impact on the overall difference;(2)The coupled health level of water resources in the Yellow River basin in terms of carrying capacity and utilization efficiency had improved over time,and the level of carrying capacity was the main limiting factor for the improvement of the coupled health level.From the perspective of spatial distribution characteristics,the spatial distribution characteristics of the coupling level of water resources carrying capacity and utilization efficiency of cities in the Yellow River basin had evolved from "low-high-low" to "low-high-high".In 2020,a healthy area appeared in the coastal cities in the lower reaches.At the same time,the distribution range of sub-healthy areas and mild disease areas had increased,and the distribution range of moderate disease areas were gradually shrunk over time.