Identifying non-point source priority management areas in watersheds with multiple functional zones

Area of Science:

• Environmental Science
• Water Resource Management
• Ecosystem Management

Background:

• Non-point source (NPS) pollution poses a significant challenge to watershed water quality.
• Effective watershed management requires understanding spatial and temporal trends in priority management areas (PMAs).
• Existing PMA studies lack comprehensiveness for watersheds with multiple water functional zones.

Purpose of the Study:

• To develop and present a novel framework for quantifying the impact of spatial assessment units on water quality within diverse water functional zones.
• To characterize multi-level PMAs for improved non-point source pollution management.
• To apply the framework in the Daning River watershed, China.

Main Methods:

• Integration of the Soil and Water Assessment Tool (SWAT) with statistical analysis.
• Quantification of spatial assessment unit perturbations on nearby water bodies.
• Application of the framework to identify and characterize PMAs across different water functional zones.

Main Results:

• The new framework effectively quantifies impacts on water quality across various water functional zones.
• PMAs identified by the framework are particularly advantageous for downstream areas, dry periods, and polluted watersheds.
• The study demonstrated the framework's utility in the Daning River watershed.

Conclusions:

• The concept of water functional zoning is crucial for effective PMA targeting in watershed management.
• The developed framework offers an optimal strategy for cost-effective NPS pollution management practices at the watershed scale.
• This approach is especially beneficial for large watersheds and extensive river systems.