Selection of Priority Tributaries for Point and Non-Point Source Pollution Management

Abstract

The Korean Ministry of Environment has established management policies for four major rivers; these policies include plans to restore ecosystems and manage hazardous materials and non-point source pollution in the watersheds. The purpose of this study was to select priority tributaries in the Nakdong River basin for immediate management under these plans by using water quality index (WQI), principal component analysis (PCA), and non-point source pollution modeling data. First, comprehensive water pollution was assessed for 22 sub-basins in the Nakdong River basin by using a WQI. Seasonal pollution was then categorized as either point or non-point source by using the PCA results based on observed water quality data, and lastly, a distributed model was developed to analyze non-point source pollutant loads. This allowed for an assessment of the degree of potential non-point source pollution from several land cover types and the selection of basins where such pollution should be managed on a priority basis. Four sub-basins (Nos. 12, 13, 19, and 21) were found to have high pollution levels, and sub-basin No. 12 had the highest non-point loading. As a result of this comprehensive basin assessment, the Geumho River was selected as the first priority tributary for management. The approach applied in this study should be useful for future efforts to develop effective strategies to improve water resources in river basins.