Ecological Network Analysis for Water Pollution Metabolism in Urban Water Use System: Case Study of Fuzhou, China

Water environment deterioration in urban environments is a critical concern in sustainable water management processes, and the method of urban water metabolism has not been developed more fully in this field. Therefore, there is a requirement to evaluate urban water metabolism with a focus on water quality for sustainable water use. In this study, information and network environ analyses in ecological network analysis (ENA) were explored to measure the water pollutant metabolism state. Six sub-basins in the old part of Fuzhou in China using data from 2016 and 2019 were selected for the case study. Results showed that (1) water pollutant metabolism amount decreased and the metabolism efficiency was improved; (2) the contribution of sub-basins III and IV for pollutant metabolism were more important than the other sub-basins; (3) the river in sub-basin III was the maximum recipient control as a sink node; and (4) ecological relations between compartments were improved for pollutant metabolism. Based on the results, we proposed five types of ENA indicators including TST, a, w(j), matrix CX, matrix sgnU, and C for the water pollutant metabolism assessment. The method developed here provided new insights to understand the production, transport, degradation, and discharge of pollutants in water use activities in urban environments, and we hope it can be helpful to improve the extension and application of the water metabolism approach in managing urban water quantity and quality in future.