Assessment of groundwater suitability for different activities in Toshka district, south Egypt

Abstract

Globally, groundwater has globally emerged as a crucial freshwater source for domestic, irrigation, and industrial needs. The evaluation of groundwater quality in the Toshka region is imperative to ensure its suitability for the extensive agricultural and industrial activities underway in this promising, groundwater-dependent development area. This is particularly significant as Egypt increasingly relies on groundwater reserves to address freshwater deficits and to implement mega-development projects in barren lands. In this study, fifty-two samples were collected from the recently drilled wells tapping into the Nubian Sandstone Aquifer (NSA) in the Toshka region. Groundwater quality was assessed through hydrochemical analysis, Piper diagram, and various indicators such as Na%, SAR, RSC, KR, MH and PI. The hydrochemical analysis revealed improved groundwater quality characteristics, attributed to continuous recharge from Lake Nasser. The Piper diagram categorised most of the water samples as "secondary salinity" water type. Almost all wells proved suitable for irrigation with only two wells unsuitable based on MH values and six wells based on KR values. Considering Total Hardness (TH) values, all samples were classified as "Soft", indicating their suitability for domestic and industrial purposes. Water Quality Index (WQI) results concluded that all samples met WHO and FAO guidelines for drinking and irrigation, respectively. Spatial distribution maps, constructed using GIS, facilitate the interpretation of the results. Regular monitoring of quality parameters is essential to detect any deviation from permissible limits.