Groundwater Quality Assessment Using Classification and Multi-Criteria Methods: A Case Study of Can Tho City, Vietnam

Abstract

This study aimed to classify groundwater quality in Can Tho City, Vietnam using groundwater quality index (GWQI), principal component analysis (PCA), and cluster analysis (CA). Groundwater samples were collected in April (dry season) and October (rainy season) in 2019 and then analyzed for thirteen parameters including pH, color, total hardness, chloride, sulfate, chemical oxygen demand, magnesium, total iron, nitrate, arsenic, lead, mercury, and coliforms. The results showed that groundwater quality in Can Tho City was contaminated with coliforms in both seasons. COD and Cl- was found exceeded the allowable limits in several wells in the dry season. The other groundwater parameters were within the permissible limits. GWQI values indicated that groundwater quality was in excellent state. The CA results revealed that groundwater quality in the dry season was more spatially varied than that in the wet season. In addition, CA revealed that groundwater monitoring sites could be reduced by 9 sites and 12 sites in the dry and wet seasons, respectively. The PCA results showed that 63.4% and 73.9% of the groundwater variation in the dry and wet seasons were explained by four PCs and three PCs, respectively. All the groundwater quality monitoring parameters were significantly and influenced by geological factors, domestic wastes, industrial and agricultural activities. Coliform should be completely treated before domestic use of groundwater in the study area. Future study should focus on investigating contribution of specific polluting sources for appropriate management measures.

Keywords

• coliforms
• groundwater
• cluster analysis
• principal component analysis
• groundwater quality index
• can tho