Abstract The expansion in human activities, the absence of running water in South Sinai province in northeastern Egypt and the high cost of seawater desalination render groundwater the essential source for potable water in this arid region. This contribution represents the integration of geophysical and hydrochemical investigations to delineate groundwater distribution and evaluate the water quality of the Cretaceous sandstone aquifer of Wadi Barqa area, Southeastern Sinai. The locations of sites, suitable for geophysical sounding measurements, were selected using digital elevation map. Vertical electrical sounding (VES) and time-domain electromagnetic sounding (TEM) measurements were carried out to determine the depth and thickness of the unsaturated and water-saturated zones as well as the groundwater quality, which were verified by calibrating the estimated electrical resistivity values with the design and logs data of eleven drilled wells next to the sites of geophysical soundings. The VES and TEM data revealed the presence of relatively thick zoned aquifer, overlain by unsaturated zone with variable thickness (83-65 m). The upper aquifer zone (25–43 m thick) is characterized by higher resistivity values (16–163 Ohm.m), reflecting fresh water signature, whereas the lower aquifer zone (122–150 m thick) has lower resistivity values (16–24 Ohm.m), indicating saturation with semi-fresh to relatively brackish water. Water samples, collected from wells taping the Nubian Sandstone aquifer, have average total dissolved solids (TDS) value of 544 mg/l. The hydrochemical parameters of these samples are consistent with NaCl water type with the majority of samples belonging to high salinity with low sodium categories. This suggests that the groundwater of the aquifer was dominated by old meteoric origin. The compositional characteristics of the groundwater of the investigated aquifer indicate suitability for domestic and irrigation purposes. However, due to the arid nature of Southeastern Sinai province, it is recommended to use this groundwater as potable water.

中文翻译：

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埃及东南西奈半岛努比亚砂岩含水层地球物理和水文地球化学调查：干旱地区地下水分布和水质评价

摘要 随着人类活动的扩大，埃及东北部南西奈省没有自来水，海水淡化成本高昂，使地下水成为该干旱地区饮用水的重要来源。这一贡献代表了地球物理和水化学调查的整合，以描绘地下水分布并评估西奈东南部 Wadi Barqa 地区白垩纪砂岩含水层的水质。使用数字高程图选择适合地球物理测深测量的站点位置。进行了垂直电测深 (VES) 和时域电磁测深 (TEM) 测量，以确定非饱和区和水饱和区的深度和厚度以及地下水质量，通过校准估计的电阻率值与地球物理测深地点附近的 11 口钻井的设计和测井数据进行了验证。VES 和 TEM 数据显示存在相对较厚的分区含水层，上面覆盖着厚度可变的非饱和带（83-65 m）。上部含水层（25-43 m 厚）的特点是电阻率值较高（16-163 Ohm.m），反映淡水特征，而下部含水层（122-150 m 厚）电阻率值较低（16-163 Ohm.m） 24 Ohm.m)，表示半淡水到相对微咸水的饱和度。从努比亚砂岩含水层的井中采集的水样的平均总溶解固体 (TDS) 值为 544 毫克/升。这些样品的水化学参数与 NaCl 水类型一致，大多数样品属于高盐度低钠类别。这表明含水层的地下水以古老的陨石成因为主。所调查含水层地下水的成分特征表明其适用于生活和灌溉目的。但是，由于西奈省东南部的干旱性质，建议将此地下水用作饮用水。