An improved export coefficient model to estimate non-point source phosphorus pollution risks under complex...

Area of Science:

• Environmental Science
• Water Resource Management
• Pollution Control

Background:

• Non-point source (NPS) pollution is a significant environmental challenge, particularly in river basins.
• Estimating NPS pollution exports and identifying pollution sources are crucial for effective control strategies.
• Precipitation and terrain significantly influence the export and transport of NPS pollutants.

Purpose of the Study:

• To establish an improved export coefficient model (IECM) for estimating agricultural and rural NPS total phosphorus (TP) exports.
• To assess TP export and identify major pollution sources within the Luanhe River Basin (LRB) in northern China.
• To provide data for developing sustainable NPS pollution prevention and control measures in semi-arid regions.

Main Methods:

• Developed and applied an improved export coefficient model (IECM).
• Utilized TP concentrations from 35 selected catchments in the LRB for model validation.
• Analyzed the contribution of different pollution categories and sources to TP export.

Main Results:

• The average TP export in the LRB was 57.20 tons in 2013, with a mean export intensity of 289.40 kg/km², significantly higher than other Chinese basins.
• TP export intensity varied across topographic regions, being highest in the South Yanshan Mountains.
• The rural population (59.44%) was the largest contributor to TP export, followed by livestock husbandry (22.24%) and land use (18.32%).

Conclusions:

• The IECM effectively estimates NPS TP pollution and its sources in the LRB.
• Rural populations, pigs, and arable land are identified as the top three sources of TP pollution.
• Findings support informed decision-making for NPS pollution control in semi-arid river basins.