Urban Water Ecosystem Health Evaluation Based on the Improved Fuzzy Matter-Element Extension Assessment Model: Case Study from Zhengzhou City, China

Abstract

The urban water ecosystem is a core foundation for the urban construction of ecological civilization. Ecosystem health is directly related to the economic development of the region and the quality of urban residents’ lives. Evaluating the health state of an urban water ecosystem is an important prerequisite for the construction of an ecologically civilized city. This study used Zhengzhou City in China as research area. Firstly, a Pressure-State-Response (PSR) model was used to construct an urban water ecosystem evaluation index system. Secondly, after analyzing the deficiency of traditional fuzzy matter-element extension model in urban water ecosystem health assessment, an improved fuzzy matter-element extension assessment model (FMEAM) was constructed by introducing the variable weight theory. Finally, using the proposed model above and the data from 2007 to 2016, this study evaluated the water ecosystem health status of Zhengzhou based on water ecosystem health integrated index (WHI). The results showed that the state of the urban water ecosystem in Zhengzhou generally improved during the study period. However, the overall level still remained low and retained an unhealthy state throughout the timeframe. The pressure on the Zhengzhou water ecosystem mainly originates from the increasing urbanization rate, the increased consumption of ecological environmental resources, and household water. Corresponding countermeasures in Zhengzhou have achieved certain results, and the health of the state’s subsystem and response subsystem has improved. However, it remains necessary to further strengthen the protection of the ecological environment, particularly with respect to water resources.