Screening of ecological impact assessment indicators in urban water body restoration process itle

Abstract Based on a river water environmental restoration project in a downtown area of the Taihu Lake Basin, this study continuously monitored the changes of water quality for two years using five indicators (shore and riparian plants, phytoplankton, amphibians, fish, and microorganisms). The variation characteristics of biological indicators were analysed over the urban water body restoration process. According to the results of water quality analysis, the water quality significantly improved during the restoration of the water environment (from inferior class V to V). With the improved water quality, the diversity of plants and amphibians changed little, which were characterized by single species and small quantities, without showing regular changes. The diversity of fish in 2015 increased significantly compared to that of 2014, and correlated significantly negatively with the concentration of water pollutants. Carps showed a stronger enrichment ability for Mn and Pb. Microbial count, γ-proteobacteria, and proteobacteria collectively served as a definitive indicator of the degree of heavy pollution in water bodies. Indicators of the ecological impact assessment in the urban water body restoration process screened in this study can be used as indicative reference indicators for the restoration status of urban water ecosystems.