Abstract The Saigon River is a tributary of the Dong Nai River and is currently being used as a water supply source for socio-economic activities in the region. However, the river’s water quality has significantly declined due to discharge activities within the basin. This study employs the Principal Component Analysis (PCA) method to assess the surface water quality of the Saigon River based on water quality monitoring data collected from 2020 to 2024 at 15 sampling locations, utilizing various water quality indicators. PCA analysis results indicate that there are three main factors explaining the water quality variation in the basin, accounting for 84.79% in the dry season and 84.32% in the rainy season. The first component (PC1), associated with biochemical oxygen demand (BOD), chemical oxygen demand (COD), and ammonia, indicates organic and nutrient pollution, mainly from domestic and industrial sources. The second component (PC2), defined by total suspended solids (TSS) and iron (Fe), reflects metal-related pollution, urban runoff, and construction activities. The third component (PC3), characterized by nitrite, highlights nitrogen cycle disruption caused by agricultural runoff or wastewater leakage. Spatial PCA analysis shows that urban waters exhibited more complex pollution levels and stronger interdependencies among pollutants compared to suburban areas. The findings of this study serve as a foundation for zoning pollution and evaluating the river’s carrying capacity, thereby supporting the management, monitoring, and effective mitigation of surface water pollution in rapidly urbanizing river basins.
Nguyen et al. (Mon,) studied this question.