Analysis of Surface Water Quality using Multivariate Statistical Approaches: A case study in Ca Mau Peninsula, Vietnam

Document Type : Original Research Paper


Department of Environmental Management, College of Environment and Natural Resources, Can Tho University, Can Tho city 900000, Vietnam


The study was conducted to assess surface water quality in Ca Mau peninsula using multivariate statistical analysis. Fifty-one water samples with the parameters of pH, dissolved oxygen (DO), total suspended solids (TSS), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonium (N-NH4+), orthophosphate (P-PO43-) and total coliform were used in the evaluation. Water quality is assessed using national standard and water quality index (WQI). The methods of cluster (CA), discriminant (DA), principal component analysis (PCA) were used to analyze the variation patterns of water quality. The surface water was contaminated with organic matters, suspended solids, nutrients, and microorganisms. DA revealed that DO, TSS, BOD5 and pH contributed 76.91% to the seasonal variation of water quality. Water quality is classified from bad to heavily polluted. CA grouped water quality into 7 clusters and DO, TSS, BOD5, COD and coliform of the clusters 1-3 were significantly higher than those of the clusters 4-7. PCA presented that PC1-PC3 was the main sources affecting water quality, explaining 85.45% of the variation in water quality. The sources of pollution can be human (domestic wastewater, waste from agriculture, fisheries, industry, landfills), natural (hydrological regime, rainwater overflow, river bank erosion). pH, DO, BOD5, COD, TSS, N-NH4+, P-PO43- and coliform have an impact on water quality and need to be continuously monitored. However, for the multivariate statistical method to be more effective, an initial data set with several water quality parameters sampling locations is needed. The current results provide scientific information and support local water quality monitoring activities.


American Public Health Association, American Water Works Association, Water Environment Federation. (1998). Standard Methods for the Examination of Water and Wastewater, 20th Ed. American Public Health Association: Washington, D.C.
Barakat, A., Baghdadi, M. E., Rais, J., Aghezzaf, B. and Slassi, M. (2016). Assessment of spatial and seasonal water quality variation of Oum Er Rbia River (Morocco) using multivariate statistical techniques. Int. Soil Water Conserv. Res., 4(4); 284-292.
Bolstad, P. V. and Swank, W. T. (1997). Cumulative impacts of landuse on water quality in a southern Appalachian watershed. J. Am. Water Resour. Assoc., 33(3); 519–533.
Cao, L., Guisen, D., Bingbin, H., Qingyi, M., Huimin, L., Zijian, W. and Fu, S. (2007). Biodiversity and water quality variations in constructed wetland of Yongding River system. Acta Ecol. Sin., 27(9); 3670-3677.
Chea R., Grenouillet G. and Lek, S. (2016). Evidence of Water quality degradation in Lower Mekong Basin Revealed by Self-Organizing Map. PLOS ONE/DOL: 10.1371/journal.pone.0145527.
Cho, K. H., Park, Y., Kang, J-H, Ki, S. J., Cha, S., Lee, S. W., and Kim, J. H. (2009). Interpretation of sea-sonal water quality variation in the Yeongsan Reser-voir, Korea using multivariate statistical analyses. Water Sci. Technol., 59(11); 2219-2226.
Chounlamany, V., Tanchuling, M. A. and Inoue, T. (2017). Spatial and temporal variation of water qual-ity of a segment of Marikina river using multivariate statistical methods. Water Sci. Technol., 66(6); 1510-1522.
Galal-Gorchev, H., Ozolins, G. and Bonnefoy, X. (1993). Revision of the WHO guidelines for drinking water quality. Ann. Ist. Super. Sanità, 29; 335-45.
Giao, N. T and Nhien, H. T. H. (2020). Phytoplankton-Water quality relationship in water bodies in the Mekong Delta, Viet Nam. Appl. Environ. Res., 42(2); 1-12.
Giao, N. T and Nhien, H. T. H. (2021). Application of GIS and multicriteria statistical techniques in assessing water quality in the coastal province of Vietnamese Mekong delta. Appl. Environ. Res., 43(3); 17-33.
Giao, N. T. (2019). The use of zoobenthos for the assessment of water quality in canals influenced by landfilling and agricultural activity. J. Viet. Env., 11(2); 33-42.
Giao, N. T. (2020). Evaluating current water quality monitoring system on Hau River, Mekong delta, Vietnam using multivariate statistical technique. Appl. Environ. Res., 2020, 42(1):14-25.
Giao, N. T. and Minh, V. Q. (2021). Evaluating surface water quality and water monitoring variables in Tien River, Vietnamese Mekong Delta. J. Teknol., 83(3); 29-36.
Giao, N. T., Nhien, H. T. H., Anh, P. K. and Ni, D. V. (2021). Classification of water quality in low lying area in Vietnamese Mekong Delta Using set pair analysis method and Vietnamese water quality index. Environ. Monit. Assess., 193(6); 1-16.
Huang, L., Jian, W., Song, X., Huang, X., Liu, S., Quian, P., Yin, K. and Wu, M. (2004). Species diversity and distribution for phytoplankton of the Pearl River estuary during rainy and dry seasons. Mari. Pollut. Bull., 49(7-8); 588-596.
Jerves-Cobo, R., Forio, M. A. E, Lock, K., Butsel, J. A., Pauta, G., Cisneros, F., Nopens, I. and Goethals, P. L. M. (2020). Biological water quality in tropical rivers during dry and rainy seasons: A model-based analysis. Ecologi. Indica, 108; 105769.
Kaiser, H.F. (1974). An index of factorial simplicity. Psychometrika, 39(1); 31–36.
Kazi, T. G., Arain, M. B., Jamali, M. K., Jalbani, N., Afridi, H. I., Sarfraz, R. A. and Shah, A. Q.  (2009). Assessment of water quality of polluted reservoir using multivariate statistical techniques: A case study. Ecotoxicol Environ Saf, 72(20); 301-9.
Lien, N. T. K., Huy, L. Q., Oanh, D. T. H., Phu, T. Q. and Ut, V. N. (2016). Water quality in mainstream and tributaries of Hau River. CTUJS, 43; 68-79. (In Vietnamese).
Ly, N. H. T. and Giao, N. T. (2018). Surface water quality in canals in An Giang province, Viet Nam, from 2009 to 2016, J. Viet. Env., 10(2); 113-119.
Mekong River Commission (MRC). (2015). Lower Mekong regional water quality monitoring report. ISSN: 1683-1489. MRC Technical Paper No.51.
Ministry of Environment and Natural Resources (MONRE). 2012. Circular No. 21/2012/TT-BTNMT dated December 19, 2012 providing for quality assurance and quality control in environmental monitoring; Hanoi, Vietnam: MONRE; 2012.
Ministry of Environment and Natural Resources (MONRE). 2015. National technical regulation on surface water quality (QCVN 08-MT: 2015/BTNMT); Hanoi, Vietnam: Ministry of Natural Resources and Environment (MONRE).
Ministry of Natural Resources and Environment (MONRE). (2015). National state of environment-surface water quality.
Ministry of Natural Resources and Environment (MONRE). (2015). National technical regulation on surface water quality (QCVN 08-MT: 2015/BTNMT). Hanoi, Vietnam: MONRE.
Ongley, E. D. (2009). Chapter 12: Water Quality of the Lower Mekong River. In: Campbell, I.C. (ed.): The Mekong: Biophysical Environment of an International. USA: Academic Press.
People's Committee of Ca Mau province. (2020). Report on the state of environment in five years (2015 -2020) of Ca Mau province, 211pages.
Phu, T. Q, Ut, V. N. (2006). Water quality for pond aquaculture. Can Tho University: College of Aquaculture and Fisheries (in Vietnamese).
Salah, E. A. M., Turki, A. M. and Othman, E. M. A. (2006). Assessment of water quality of Euphrates River using cluster analysis. J. Environ. Prot., 3; 1629–1633.
Shrestha, S. and Kazama, F. (2007). Assessment of surface water quality using multivariate statistical techniques: a case study of the Fuji river basin. Environ Model Softw., 22; 464-75.
Singh, K. P., Malik, A. and Sinha, S. (2005). Water quality assessment and apportionment of pollution sources of Gomti river (India) using multivariate statistical techniques – a case study. Anal. Chim. Acta, 538; 355–374.
Truc, D.T., Phat, P. H., Nam, N. D. G., Toan, P. V. and Tri, V. P. D. (2019). Surface water quality of Tien River flowing through Tan Chau area, An Giang province. CTUJS, 55; 12-22.
Tuan, D. D. A., Thu, B. A. and Trung, N. H. (2019). Assessing quality of surface water for urban water supply source for Soc Trang City. CTUJS, 4A; 61-70. (In Vietnamese).
United Nations Children's Fund (UNICEF). (2008). UNICEF Handbook on Water Quality. New York: United Nations Children's Fund.
Ut, V.N., Loan, N. B., Giang, H. T., Oanh, D. T. H., Lien, N. T. K., Quoc, N. B., Ngoan, N. V., Hoa, A. V. and Tu, P. T. C. (2013). Study on measures to limit the growth of Limnoperna fortunei living on Cipangopaludina lecithoides in Cho Lach district, Ben Tre. Final report on ministerial-level projects, 100 pages.
Varol, M. (2020). Spatio-temporal changes in surface water quality and sediment phosphorus content of a large reservoir in Turkey. Environ. Pollut., 259; 113-860.
Vega, M., Pardo, R., Barrado, E. and Debán, L. (1998). Assessment of seasonal and polluting effects on the quality of river water by exploratory data analysis. Water Res., 32; 3581-92.
Vietnam Environment Administration. (2018). Water quality - Sampling Part 6: Guidance on sampling of rivers and streams (TCVN 6663-6:2018). Hanoi, Vietnam: Ministry of Science and Technology
Vietnam Environment Administration. (2019). Decision 1460/QD-TCMT dated November 12, 2019 regarding the promulgation of Technical Guidelines for calculation and publication of Vietnam's water quality index.
Wijeyaratne, W. M. D. N. and Kalaotuwave, K. M. B. P. P. (2017). Evaluation of the water and sediment quality of a lotic water-body in the western coastal region of Sri Lanka using Rapid Bioassessment Protocol II (RBP II) of benthic macroinverterbrates. Sri Lanka J. Aquat. Sci. 22(2); 85-97.
World Health Organization (WHO). (2008). Guidelines for drinking-water quality - Volume 1: Recommendations Third edition, incorporating first and second addenda. Geneva: World Health Organization.
Zeinalzadeh, K. and Rezaei, E. (2017). Determining spatial and temporal changes of surface water quality using principal component analysis. J. Hydrol. Reg. Stud., 13; 1-10.