Urban water environment carrying capacity based on VPOSR-coefficient of variation-grey correlation model: A case of Beijing, China

Abstract

In order to gain an in-depth understanding of the change of urban water environment carrying capacity (WECC), we proposed a framework system of VPOSR (vigor, pressure, organization, state and resilience subsystem), which was used to construct an evaluation index system for urban WECC. The coefficient of variation grey correlation method was employed to analyze the urban WECC of each subsystem of Beijing, China from year 2008 to 2016. The coupling coordination degree of each subsystem were calculated. The results show that: (1) The evaluation index value of WECC in Beijing is on the rise from 0.3560 in 2008 to 0.7877 in 2016, which suggests that the index of WECC of Beijing is improving, and the social and economic development is within an affordable range of the water environment. (2) The rate of ecological water usage, the proportion of energy conservation and environmental protection in local financial expenditure and the per capita water resources are the top three indicators with great impact on WECC. (3) The correlation degree index of vigor subsystem, pressure subsystem, organization subsystem, state subsystem, and resilience subsystem with water environment carrying capacity system are 0.0958, 0.1169, 0.0252, 0.0328 and 0.2962 respectively. The subsystem with strong correlation with water environment is resilience subsystem, followed by pressure subsystem. (4) According to the index distribution of coordination degree, the coordination degree level is between 0.4032 and 0.4458, and the coupling degree of each subsystem is above 0.8, which belong to the high coupling level.