A spatial optimal allocation method considering multi-attribute decision making and multiple BMPs random combination...

Area of Science:

• Environmental Science
• Water Resource Management
• Ecological Engineering

Background:

• Non-point source pollution is a significant challenge in watershed management.
• Effective allocation of best management practices (BMPs) requires considering objective function weights and restrictive conditions.
• Existing methods often lack spatial optimization and multi-attribute decision-making for combined BMPs.

Purpose of the Study:

• To develop a novel framework for spatial optimal allocation of multiple BMPs in watersheds.
• To integrate multi-attribute decision-making for cost-effective pollution control.
• To consider combined reduction rates of total nitrogen (TN) and total phosphorus (TP) alongside BMP costs.

Main Methods:

• Utilized the Soil and Water Assessment Tool (SWAT) and Non-dominated Sorting Genetic Algorithm II (NSGA-II) for multi-objective optimization.
• Integrated Entropy Weight Method (EWM) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) for weighting TN and TP reduction.
• Evaluated four BMP categories (tillage, nutrient management, vegetative filter strips, landscape management) in the Jing River Basin (JRB).

Main Results:

• Achieved average reduction rates of 9.77% (tillage), 10.53% (nutrient management), 16.40% (filter strips), and 14.27% (landscape management).
• Developed BMP allocation schemes stratified into low, medium, and high-cost scenarios, with varying primary BMPs and sub-basin coverage.
• Demonstrated trade-offs between implementation costs and pollution reduction efficiencies across the financial scenarios.

Conclusions:

• The innovative framework facilitates cost-effective implementation of watershed pollution control measures.
• The methodology provides a beneficial approach for selecting suitable conservation practices based on local attributes and cost-benefit analysis.
• The study offers a valuable decision-support tool for watershed management and non-point source pollution mitigation in diverse regions.