Dynamic Evaluation of Ecological Environment Quality in Coastal Cities from the Perspective of Water Quality: The Case of Fuzhou City

Urbanization has led to enormous pressure on the urban ecological environment, especially in coastal cities. It is important to evaluate the ecological quality of coastal cities. We compared the remote sensing-based ecological index (RSEI) and the water benefit-based ecological index (WBEI) indices of Fuzhou City, and selected the WBEI to assess the changes in the quality of the ecological environment in Fuzhou City from 2000 to 2020 and analyzed the relevant changes in land intensity. The results show that (1) the Fuzhou WBEI outperforms the RSEI in the evaluation of ecological quality in the study area, since the WBEI takes into account water efficiency and can more accurately represent the ecological environment of coastal cities; (2) during 2000-2020, the overall trend of ecological quality in Fuzhou is better, with nonsignificant decreasing areas in the western and northern mountainous areas and a significant increasing trend in the southeast coast; and (3) different land use types influence the urban ecological environment quality, with forests and man-made surfaces having a good correlation with the WBEI. The increase in forests contributes to the improvement of urban ecological environment quality, and the conversion of high-intensity arable land and construction land decreases urban ecological environment quality. This study can provide a basic reference for the assessment of ecological environment quality in Fuzhou City and provide experience for the ecological environment assessment of coastal cities.