Ecological Health Assessment of an Urban River: The Case Study of Zhengzhou City, China

Abstract

Urban river ecological health assessment is an effective means to manage urban rivers, and combining principles of landscape ecology can provide new help for the ecological restoration of urban rivers and improving their ecosystem service value. From the perspective of important functions of ecosystems, based on typical sample site investigations of different river sections, questionnaire surveys, and remote sensing technology, a fuzzy comprehensive evaluation model based on the factor analysis method was used to construct an indicator system that can quantitatively reflect the ecological health of urban rivers. This comprehensive evaluation index system includes five major functions: social function, habitat and corridor function, water ecological function, water landscape function, and spatial enclosure function. The study identified key areas, key rivers, key river sections, and main indicator projects for the ecological restoration of the urban river landscape corridors in Zhengzhou. The study results also showed that the urban river landscape corridors in Zhengzhou have prominent problems in social function, water ecological function, and habitat and corridor function, and 62.1% of the river sections are currently in a sub-healthy state. The flood control function, eutrophication of water body, naturalization rate of revetment, and five other indicators in the old city district are significantly lower than those in the new city district, and the old city district should be the focus of the ecological restoration of urban river corridors. From the evaluation of the ecological health status of typical river sections, the Jinshui River and Xionger River have a larger number of river sections that urgently need restoration. This study provides a reference for the ecological restoration of urban rivers in Zhengzhou, a rapidly urbanizing region, and has reference significance for the construction of water landscapes in small and medium-sized cities with low levels of urbanization.