Selection of priority watershed for water environment management

Area of Science:

• Environmental Science
• Water Resource Management
• Ecology

Background:

• Water quality in the Yeongsan River basin has degraded, with monitoring data showing exceedances of target standards in middle and lower reaches over the past decade.
• Identifying priority management areas is crucial for effective water resource management and pollution control.

Purpose of the Study:

• To identify and rank priority management watersheds within the Yeongsan River basin for targeted water quality improvement efforts.
• To assess the impact of point source (PS) and non-point source (NPS) pollution on water quality.

Main Methods:

• Analysis of water quality data over a decade.
• Identification of pollution sources and loads based on land use characteristics (urban vs. rural).
• Load duration curve (LDC) analysis and multivariate log-linear analysis to evaluate PS and NPS impacts.
• Calculation of standard and integrated indicators for watershed ranking.

Main Results:

• Water quality standards were exceeded in the middle and lower Yeongsan River.
• Watershed W-1 (urban) showed high pollution from residential, industrial, and urban land use, while W-6 (rural) had high loads from livestock, aquaculture, and agriculture.
• LDC analysis confirmed exceedances across all flow ranges, indicating the need to manage both PS and NPS pollution.
• Priority management rankings were established: W-1 > W-6 > W-3 > W-4 > W-2 > W-5 > W-7 > W-8.

Conclusions:

• Both point source and non-point source pollution significantly impact water quality in the Yeongsan River basin.
• Watershed W-1 and W-6 are identified as high-priority areas requiring immediate management interventions.
• The study provides a framework for future diagnostic assessments and the development of effective water quality management strategies.