GIS-Based Spatial Distribution of Groundwater Quality in the Western Nile Delta, Egypt

Groundwater (GW) is an important source of drinking and irrigation water in Egypt, especially in some areas where the surface water is insufficient or unavailable. The present study presents the multivariate statistical analysis of groundwater quality of the western Nile Delta (ND) aquifer in order to investigate the factors controlling the groundwater quality. Also, it presents the suitability of groundwater in the western ND for drinking and irrigation. The available data, of 108 GW wells, includes 21 physicochemical parameters for each well (GW sample), viz., EC, TH, TDS, pH, Ca, Mg, Na, K, CL, SO₄, HCO₃, CO₃, Fe, Mn, Zn, Cu, Pb, Cd, Cr, NO₃, and NH₄. Nineteen physicochemical parameters are used as inputs for multivariate analysis. The World Health Organization (WHO) and Egyptian standards (ES) were used as reference standards for the suitability of water for drinking purposes. TDS, SAR, Na %, RSC, Mg %, PI %, KI, CRI, and CR were used to evaluate groundwater suitability for irrigation. ArcGIS was utilized to detect and visualize the spatial classification maps of different parameters. Multivariate analysis showed the existence of up to four significant factors which account for 77.0% of the total variance of hydrochemistry data. The computed water quality index (WQI) shows that 45.37% and 66.67% of GW wells fall in good drinking water categories according to WHO and ES, respectively. According to values of TDS, RSC, SAR, and PI, more than 58.83% of groundwater wells are suitable for irrigation. It is recommended to take the necessary actions to control the pollution sources of groundwater in western ND.