Hydrochemical and statistical study of water quality in karstic water system (southwest China)

Groundwater quality assessment is important to ensure sustainable safe use of water. In the region of southwest China, karstic water represents the main source of water supply for drinking, agriculture and industry. A multivariate statistical technique, cluster analysis, was used to assess the in Houzhai karstic water system, southwest China. 17 samples were collected from upstream to downstream. The collected samples were analyzed for a total of 9 water quality parameters including pH, TDS, sulfate, chloride, bicarbonate, calcium, magnesium, sodium, Total hardness..Q-mode hierarchical cluster analysis (HCA) was then applied to the standard z-scores of the data and four spatial groundwater types were distinguished. The result show the most predominant water type in cluster 1 and 3 is the Ca-HCO₃ water type. Cluster 2 indicates the marlstone and sulfate strata are the predominate factors influencing the water quality.