Search Results (4)

Water quality is crucial to the environmental system and thus its chemistry is important, and can be directly related to the water’s source, the climate, and the geology of the region. This study focuses on analyzing the hydrochemistry of specific locations within the Dakhla Oasis in Egypt. A total of thirty-nine groundwater samples representing the Nubian Sandstone Aquifer (NSSA) and seven surface water samples from wastewater lakes and canals were collected for analysis. Key parameters such as pH, electrical conductivity (EC), and total dissolved solids (TDS) were measured on-site, while major ions and trace elements (Fe⁺² and Mn⁺²) were analyzed in the laboratory. The water quality index (WQI) method was employed to assess the overall water quality. Hydro-chemical facies were investigated using Piper’s, Scholler’s, and Stiff diagrams, revealing sodium as the dominant cation and chloride, followed by bicarbonate as the dominant anion. The hydro-chemical composition indicates that Na–Cl constitutes the primary water type in this study. This points to the dissolution of evaporates and salt enrichment due to intense evaporation resulting from the region’s hyper-aridity. In groundwater samples, the order of hydro-chemical facies is HCO₃⁻ > Cl⁻ > SO₄⁻² > Na⁺ > Ca⁺² > K⁺ > Mg⁺², while in wastewater samples, it is Cl⁻ > Na⁺ > SO₄⁻² > HCO₃⁻ > Ca⁺² > Mg⁺² > K⁺. When considering iron and manganese parameters, the water quality index (WQI) values suggest that most groundwater samples exhibit excellent to good quality but become poor or very poor when these elements are included. This study could prove valuable for water resource management in the Dakhla Oasis. Full article

Groundwater is the single source of water in El-Dakhla Oasis, western desert, Egypt. The main objective of this study is an assessment of groundwater in the area for agriculture and drinking compared to Egyptian and World Health Organization criteria. Most the contamination of water in the study area comes from human and agricultural activities. Thirty soil profiles were studied in the area and we assessed soil quality. Seventy-four samples were taken from the area’s groundwater wells to assess the chemical characteristics of the groundwater. Moreover, the contamination of groundwater by farming and anthropogenic activities was assessed using a land use/land cover (LULC) map. Nine standard water criteria were determined to assess groundwater quality for agriculture. Furthermore, the resulting risk to human health and agricultural crops has been addressed. Therefore, the drinking quality of groundwater samples is graded as low as the hydrochemical study showed high TH, EC, TDS, Ca²⁺, Mg²⁺, Mn²⁺, and Fe²⁺ contents of 40.5%, 2.7%, 1.4%, 3.8%, 1.6%, 86.5%, and 100%, respectively. Human health is risked by drinking this water, which negatively affects hair, skin, and eyes, with greatest exposure to enteric pathogens. Using these criteria, the majority of groundwater samples cause harmful effects on soil types and are toxic to sensitive crops (vegetable crops). In conclusion, the output of this research is a map showing groundwater suitable for consumption and agriculture in El-Dakhla Oasis based on all indices using the Geographic Information Systems (GIS) model. Additionally, there was evidence of a linear relationship between soil quality and irrigation water quality (R² = 0.90). This emphasis on tracking changes in soil/water quality was brought on by agricultural practices and environmental variables. Full article

This study investigates the distribution of natural radioactivity and geological, geochemical, and environmental risk assessments of phosphorite deposits to determine their suitability for international applications (such as phosphoric acid and phosphatic fertilizers). The examined Late Cretaceous phosphorite deposits belong to the Duwi Formation, which is well exposed on the southern scarp boundary at the central part of Abu Tartur Plateau, Gebel Qulu El Sabaya, East Dakhla Oasis. This formation is classified into lower phosphorite, middle shale, and upper phosphorite members. The lower phosphorite ranges in thickness from 2 to 3.5 m and mainly comprises apatite (possibly francolite), dolomite, calcite, quartz, hematite, anhydrite, and kaolinite. They contain an average concentration of CaO (38.35 wt.%), P₂O₅ (24.92 wt.%), SiO₂ (7.19 wt.%), Fe₂O₃ (4.18 wt.%), MgO (3.99 wt.%), F (1.59 wt.%), Al₂O₃ (1.84 wt.%), Na₂O (1.33 wt.%), and K₂O (0.22 wt.%). Natural radioactivity and radiological parameters were investigated for fifteen samples of phosphorites using a NaI (Tl) scintillation detector. Absorbed dose rates, outdoor and indoor annual effective dose, radium equivalent activity, external and internal hazard, and excess cancer risk values are higher than the recommended levels, reflecting that exposure to these deposits for a long time may lead to health risks to human organs. Full article

In the course of the last ten years, the North Kharga Oasis–Darb Ain Amur Survey team, led by Salima Ikram (American University in Cairo), has been exploring a network of interconnected desert paths in Egypt’s Western Desert, known as Darb Ain Amur. These marked paths run between Kharga Oasis and Dakhla Oasis, linking them to Darb el-Arbain, a notorious caravan route facilitating contacts between Egypt and sub-Saharan Africa since prehistoric times. Ancient travelers using the Darb Ain Amur spent several days in the midst of the Western Desert and were thus forced to use areas around sandstone rock outcrops as makeshift stopovers or camping sites. During these much-needed breaks, ancient travelers identified accessible, inscribable surfaces on the towering sandstone massifs and left on them their personalized markings. In this essay, I examine two short rock graffiti carved by such travelers in a site north of Kharga Oasis, focusing on the types of information one may extract from such ancient epigraphic materials. Full article