Water quality index and geographic information system to assess the groundwater quality of taluka Matiari, Sindh, Pakistan

The study reports the groundwater quality assessment of taluka Matiari for irrigation and human consumption. A total 37 water samples collected from various union councils of taluka Matiari were analyzed for physicochemical parameters, anions, essential metals, trace metals, and toxic elementsfluoride and arsenic. The results indicated that arsenic in 35% and fluoride in 27% of samples were higher than the WHO limits. GIS maps of toxic elements were drawn and showed that most samples were not appropriate for human consumption. Samples were also identified for water quality index (WQI), cluster analysis, Chadha diagram, correlation matrix, Piper diagram, Gibbs diagram, and principal component analysis (PCA) using graphical approaches and statistical methods. The groundwater quality of taluka Matiari based on WQI values indicated that 21 (56.76%) samples were considered “poor” for human consumption. Piper diagram indicated that most water samples were rich in mixed Ca2+-Mg2+-Cl- and Ca2+-Na+-HCO-3-type water. In PCA, four components were extracted for data set that accounted for 80.41% of cumulative variance. Gibbs diagram indicated that anions and cations in water samples were in rock domination as compared to precipitation and evaporation. Chadha diagram indicated the properties and dominance of weak acids and alkaline earth than strong acids and alkali metals. The calculated parameters for irrigation indicated that most of the samples of Matiari were suitable for agricultural purposes. Still, the presence of arsenic in groundwater may result in the transfer of arsenic into the food chain.