Coupled multivariate statistical analysis and WQI approaches for groundwater quality assessment in Wadi El-Assiuty downstream area, Eastern Desert, Egypt

Abstract

Groundwater is the primary source of fresh water for agriculture and other purposes in the Wadi El-Assiuty area; therefore, the preservation of its supply and quality is of great importance. The present study aims to evaluate the groundwater quality in the newly reclaimed parts of Wadi El-Assiuty by integrating hydrochemical data, multivariate statistical analyses, and a water quality index (WQI). In this study, 48 groundwater samples were collected and analyzed for 12 physicochemical parameters. Multivariate statistical approaches, including a correlation matrix, factor analysis, and hierarchical cluster analysis, were applied to differentiate the source of the water quality variation and determine the cause of groundwater deterioration. The factor analysis identified three main factors describing the groundwater quality in the study area, and the cluster analysis indicated two main distinct clusters of the analyzed variables. The spatial variation maps of the analyzed parameters were developed using interpolation techniques within a geographic information system environment. The WQI was applied according to the chemical drinking-water quality standards of the World Health Organization (WHO) with respect to the 12 parameters measured to evaluate the suitability of the groundwater for human consumption. The resultant WQI showed that approximately 54% of the collected groundwater samples were of an acceptable quality for human consumption with respect to the 12 parameters measured. The suitability of groundwater for irrigation was evaluated according to the salinity hazard (as electrical conductivity, EC), sodium adsorption ratio (SAR), sodium percentage (Na%), and magnesium hazard (MH). From the results, 40% of the collected samples were “permissible” for irrigation with respect to the EC, 82% were “good” to “excellent” with respect to the SAR values, 29% were “permissible” with respect to the Na%, and 90% were “suitable” with respect to the MH.