Application of Multivariate Statistical Techniques in the Assessment of Surface Water Quality in Dak Lak Province, Vietnam

Water quality monitoring is crucial for assessing water quality and identifying sources of water pollutants. This study assessed the surface water quality in Dak Lak province, Vietnam using multivariate statistical techniques. Pearson correlation, water quality index (WQI), principal component analysis (PCA), and cluster analysis (CA) were determined based on various physical, chemical, and biological indicators. The study found that BOD5 concentrations exceeded permissible limits in 80% of river water samples and 36% of lake water samples. Meanwhile, all samples met the allowable limits for N-NO3–. The assessment revealed that surface water pollution in the region is due to both natural and human activities. TSS mainly originated from natural processes or mineral exploitation, while BOD5 and COD were primarily from domestic or waste treatment. N-NO2–, N-NO3–, N-NH4+, o-PO43– were traced back to domestic and industrial wastewater, and coliforms were from domestic and non-human sources. Water samples from areas with high population density had lower WQI values than areas surrounded by agriculture fields and sparse populations. Finally, the study noted that water flow with high pollutant concentrations during the rainy season. These findings are expected to provide valuable insights into surface water pollution in Dak Lak province.