Evaluation of Groundwater Quality Variations Using Geographical Information System (GIS) and Multivariate Statistical Techniques: A Case Study from Qa’Jahran Basin, Dhamar, Yemen

The current study investigates the water quality of the water resources in Qa’Jahran basin, Dhamar, Yemen. Thirty water wells with a depth ranging from 100 to 600 m below ground level were used to collect water samples. A total of seventeen water quality parameters were measured during 2019, allowing investigation of spatial variation and indication of potential pollution sources. It is essential to have adequate understanding on the interaction effect, trends, and the correlation structure of these parameters to control water quality. Geographical Information System (GIS) and multivariate statistics techniques were used to understand the water resource quality and generate a water quality index map of Qa’Jahran basin. Based on multivariate statistical analysis, strong correlations were observed between total dissolved solids (TDS), conductivity, chloride, total alkalinity, bicarbonate, sodium, and chloride. Sodium has strong correlation with total alkalinity, chloride, and bicarbonate, while it has moderate correlation with fluoride. On the other side, principal component analysis shows that 85.22% of the overall variances were explained by four major principal components. Accordingly, 52% of the data were required to explain 85.22% of total variances as shown by the factor analysis indicating significant data reduction was resulted in this study. According to the water quality index (WQI), most of the water samples were classified as excellent to good for drinking purpose.