Balancing water quality impacts and cost-effectiveness for sustainable watershed management

Abstract

Balancing clean water and economic growth remains challenge to achieve the Sustainable Development Goals (SDGs) issued by the United Nations. In this study, the water quality impacts and cost-effectiveness analysis of catchment actions were integrated by a new proposed watershed management framework (WAM-SDGs). The source appointment and control practices were incorporated based on physical-based model and heuristic algorithm. The tradeoffs between different targets were balanced using multiple attribute decision-making (MADM) and Pareto score approaches. The method was tested in two paired catchments including typical urban and agricultural catchments in China. The results indicated that 1) the cost-effectiveness and reliability of catchment action was improved by 4% and 3.3% compare to traditional methods. 2) The restriction of urban pollution is mainly attributable to strong spatial heterogeneity, while that of agricultural pollution control is attributed to lack of investment. 3) For water quality improvement, sources and sinks of pollutants are quantified and used as priority areas for catchment action. Due to high pollution intensity and control reliability, urban catchments should be given priority and agricultural catchments are more cost-effectiveness when fund is no longer a limiting factor. The economic-based and water-quality-based protection strategies are suggested for urban and agricultural catchment, respectively. This new framework could be extended to other catchments for global sustainable development.