An integrated assessment approach for fossil groundwater quality and crop water requirements in the El-Kharga Oasis, Western Desert, Egypt

Study region: The El-Kharga Oasis in the Western Desert of Egypt is selected as the study area due to its hyberarid climate condition and water scarcity. In this region, the fossil groundwater is the main water source; therefore, preserving groundwater quality and quantity is mandatory. Study focus: This study evaluated groundwater suitability for irrigation purposes and assessed the water requirements of cultivated crops to optimize the water supply in hyperarid climate regions. In total, 79 deep groundwater samples were hydrochemically tested to determine the suitability for irrigation by assessing the key water quality parameters. Spatial distribution maps of all chemical parameters, such as pH, EC, SAR, RSC, SSP, TDS, total hardness, Na+, K+, Ca++, Mg++, Fe, Mn, Cl-, and SO4—, were developed. The FAO CROPWAT 8.0 model, based on the Penman–Monteith equation, was used to forecast agricultural water requirements for three years, 2010, 2011, and 2012. New hydrological insights for the region: The groundwater had medium salinity and low sodium in 84% of the cases. In comparison, high salinity was found in 16% of the samples, indicating that groundwater can be used for many soil types with a low risk of exchangeable sodium. Except for 15 of the 79 wells, all groundwater samples had chloride concentrations less than 100 mg/l. The sulfate ion distribution map showed a low sulfate ion content in the extreme western south. The total annual irrigation water requirements of all crops for 2010, 2011 and 2012 were 199.4, 215.1, and 231.7 million m3/year, respectively, reflecting a gradual increase of approximately 16.57 million m3/total area/year due to the expansion of the cultivated area. The analysis showed that modern irrigation systems reduced the amount of irrigation water by 32% and increased the cultivated area by 45% compared to conventional irrigation methods. Severe groundwater depletion occurred during the dry season from March to July, which exacerbated the water stress in the study region. The results confirmed that the region is under water stress. Accordingly, water conservation is urgently recommended

Detection of Groundwater Pathways to Monitor Their Level Rise in Osirion at Abydos Archaeological Site for Reducing Deterioration Hazards, Sohag, Egypt Using Electrical Resistivity Tomography Technique

Climatic changes because of groundwater levels rising near the archaeological sites became a fundamental issue in Egypt. The problem will affect the deterioration of the stone foundations of the temples and any archaeological features, which will affect their deformation, changing their features, and their archaeological and architectural importance. Osirion in Abydos archaeological place, west of Sohag Governorate, undergoes this problem where the level of ground water increases west of this site in the spring season. Solving this problem will help to preserve the antiques at the Abydos site and, in particular, the Osirion and its surrounding area. It is important to understand the hydrostratigraphic conditions of the Abydos site and its surroundings. The main objectives of the work are: (1) characterizing the subsurface succession and lithology; (2) identifying the sources responsible for the groundwater level rising near the Osirion, and groundwater assessment distribution and water table depth; and (3) evaluating the subsurface location and geometry of any paleochannels that may represent conduits for groundwater flow pathways to join the water to the studied site. All this information will aid the officials to decide and make future solutions to solve these problems. To achieve these goals, the authors implemented an advanced geophysical technique, namely electrical resistivity tomography (ERT) investigations in conjunction with the existing boreholes data. The main outcomes of this work are 2D and 3D representations of the resistivity distributions, which reflect a full picture about the subsurface engineering layers, including details of the lithology of the study site. The subsurface succession includes four geoelectrical zones that were recognized. The water table level in the study site varies from 5 m to 14 m as confirmed from all the ERT profiles together with the available borehole data. A three-dimensional visual representation of the water-bearing muddy sand formation shows the presence of a potential channel in the north-east direction and its location, which is responsible for delivering the groundwater from the Nile River to the Osirion site. This result is in consistent with archaeological studies conducted in the Osirion site, where there are ancient archaeological text and drawings on the temple walls and columns. By defining the direction of the groundwater pathways, the authors recommend the decision-makers to take the engineering precautions to try to prevent the groundwater from reaching the important archaeological sites by establishing the dams and partitions. In addition, they should monitor and control the groundwater level changes around the archaeological foundations by implementing all the necessary measurements to prevent the soil subsidence and foundation collapse, and establishing a dewatering system network

Geoarchaeological Investigation of Abydos Area Using Land Magnetic and GPR Techniques, El-Balyana, Sohag, Egypt

Abydos Temple is one of Egypt’s most significant sites which has a long history that dates back to the ancient monarchy and continued until the coming of Islam and also served as one of Egypt’s most significant ancient royal and high-ranking official burial sites. The main objective of this work was discovering more archaeological features buried underground such as ancient walls, monuments, and tombs. This objective was achieved using two near surface sophisticated geophysical techniques, namely ground magnetic survey and ground penetrating radar (GPR). This site was surveyed firstly using ground magnetic survey as reconnaissance stage and the locations which contain potential anomalies were resurveyed using GPR technique for determination the depth and the geometry of this potential targets. This site was divided into four regular grids and GPR model SIR-4000 equipment with 200 MHz central frequency antenna was used in this survey. The output of the magnetic survey is a total magnetic anomaly map which was filtered using High pass (HP) and first vertical derivative (VFD) techniques to extract the residual component of the shallow objects which may be archaeological targets. The results of the magnetic methods showed a group of anomalies which appeared on the residual map and were attributed to archaeological features by comparing them with the current excavated objects in and around the site. Their geometrical shapes and depths were estimated using source parameter imaging (SPI) and analytical signal (AS) techniques in Geosoft Oasis Montag Software. The estimated depth of these objects is between 1–3 m. Several hyperbolic shapes appeared in the radargram sections, indicating the possibility of probable buried archaeological objects. These potential objects can be found at depths of 2 to 4 m below the ground surface. The presence of eight probable targets associated with archaeological features at depths between 1–4 m is therefore the most likely outcome from both magnetic and GPR approaches. Therefore, this site contains potential archaeological targets which need confirmation by excavation. These results will influence domestic and foreign tourism in Egypt, leading to an increase in visitors and a rise in Economy

Detection of Groundwater Pathways to Monitor Their Level Rise in Osirion at Abydos Archaeological Site for Reducing Deterioration Hazards, Sohag, Egypt Using Electrical Resistivity Tomography Technique

Climatic changes because of groundwater levels rising near the archaeological sites became a fundamental issue in Egypt. The problem will affect the deterioration of the stone foundations of the temples and any archaeological features, which will affect their deformation, changing their features, and their archaeological and architectural importance. Osirion in Abydos archaeological place, west of Sohag Governorate, undergoes this problem where the level of ground water increases west of this site in the spring season. Solving this problem will help to preserve the antiques at the Abydos site and, in particular, the Osirion and its surrounding area. It is important to understand the hydrostratigraphic conditions of the Abydos site and its surroundings. The main objectives of the work are: (1) characterizing the subsurface succession and lithology; (2) identifying the sources responsible for the groundwater level rising near the Osirion, and groundwater assessment distribution and water table depth; and (3) evaluating the subsurface location and geometry of any paleochannels that may represent conduits for groundwater flow pathways to join the water to the studied site. All this information will aid the officials to decide and make future solutions to solve these problems. To achieve these goals, the authors implemented an advanced geophysical technique, namely electrical resistivity tomography (ERT) investigations in conjunction with the existing boreholes data. The main outcomes of this work are 2D and 3D representations of the resistivity distributions, which reflect a full picture about the subsurface engineering layers, including details of the lithology of the study site. The subsurface succession includes four geoelectrical zones that were recognized. The water table level in the study site varies from 5 m to 14 m as confirmed from all the ERT profiles together with the available borehole data. A three-dimensional visual representation of the water-bearing muddy sand formation shows the presence of a potential channel in the north-east direction and its location, which is responsible for delivering the groundwater from the Nile River to the Osirion site. This result is in consistent with archaeological studies conducted in the Osirion site, where there are ancient archaeological text and drawings on the temple walls and columns. By defining the direction of the groundwater pathways, the authors recommend the decision-makers to take the engineering precautions to try to prevent the groundwater from reaching the important archaeological sites by establishing the dams and partitions. In addition, they should monitor and control the groundwater level changes around the archaeological foundations by implementing all the necessary measurements to prevent the soil subsidence and foundation collapse, and establishing a dewatering system network

Geoarchaeological Investigation of Abydos Area Using Land Magnetic and GPR Techniques, El-Balyana, Sohag, Egypt

Abydos Temple is one of Egypt’s most significant sites which has a long history that dates back to the ancient monarchy and continued until the coming of Islam and also served as one of Egypt’s most significant ancient royal and high-ranking official burial sites. The main objective of this work was discovering more archaeological features buried underground such as ancient walls, monuments, and tombs. This objective was achieved using two near surface sophisticated geophysical techniques, namely ground magnetic survey and ground penetrating radar (GPR). This site was surveyed firstly using ground magnetic survey as reconnaissance stage and the locations which contain potential anomalies were resurveyed using GPR technique for determination the depth and the geometry of this potential targets. This site was divided into four regular grids and GPR model SIR-4000 equipment with 200 MHz central frequency antenna was used in this survey. The output of the magnetic survey is a total magnetic anomaly map which was filtered using High pass (HP) and first vertical derivative (VFD) techniques to extract the residual component of the shallow objects which may be archaeological targets. The results of the magnetic methods showed a group of anomalies which appeared on the residual map and were attributed to archaeological features by comparing them with the current excavated objects in and around the site. Their geometrical shapes and depths were estimated using source parameter imaging (SPI) and analytical signal (AS) techniques in Geosoft Oasis Montag Software. The estimated depth of these objects is between 1–3 m. Several hyperbolic shapes appeared in the radargram sections, indicating the possibility of probable buried archaeological objects. These potential objects can be found at depths of 2 to 4 m below the ground surface. The presence of eight probable targets associated with archaeological features at depths between 1–4 m is therefore the most likely outcome from both magnetic and GPR approaches. Therefore, this site contains potential archaeological targets which need confirmation by excavation. These results will influence domestic and foreign tourism in Egypt, leading to an increase in visitors and a rise in Economy

The structures control the evolution of molasse basins and alteration zones occurrences in the northwestern sector of the Central Eastern Desert of Egypt

Abstract Integration between the analyses of both fieldwork and remote sensing dataset were employed to assess the structural evolution of molasse basins and explore gold mineral deposits in the El Qash area, Central Eastern Desert of Egypt. Sandstone, mudstones, wacke, and pebbly conglomerates make up most of the sediments in the molasse basins. The younger basins (595–575 Ma) are small, less weathered, and mostly Dokhan detritus-filled basins compared to the larger older basins (> 625–605 Ma), which have more weathered sources mainly of arc metavolcanics. The molasse basins appear to have originated in a north–south regional extensional setting, characterized by a prolonged period of left-lateral transtension combined with the formation of NNE-trending synformal folds during an ENE–WSW compression phase. Notably, en-echelon arrays of normal faults, oriented perpendicular to the boundary of the strike-slip shear zone, are a recurring feature in basins formed through transtension. Furthermore, oblique NE-SW compression played a role in generating SW-dipping thrust faults and regional folding with NW–SE orientation, along with the reactivation of transtensional normal faults in a reverse manner. Multispectral satellite imagery data and radar data are used to map the relevant lithological units, structures, and hydrothermal alteration zones. This study concludes that the regions where gold deposits may be explored in connection with prospecting alteration minerals include the area around the ophiolitic assemblages, and the granitic intrusions, in addition to the felsite and the molasse sediments contacts

Evaluation of Engineering Site and Subsurface Structures Using Seismic Refraction Tomography: A Case Study of Abydos Site, Sohag Governorate, Egypt

Because of the strategic importance of the Abydos archaeological site in Egypt as a source of wealth for Egyptian tourism, this study was concerned with carrying out geophysical measurements to detect subsurface succession and measure variations in the geotechnical engineering features of the soils/rocks in order to protect this significant area. The findings will assist geologists and seismologists in collaborating with archaeologists for future site development, revitalization, and investment. The primary objectives of this work were to determine the subsurface lithology, evaluate the engineering geotechnical properties of soils/rocks, identify the layer thicknesses, and identify the site class by calculating Vs30. To achieve these goals, seventeen (17) seismic refraction tomography (SRT) P- and S-wave measurements were executed in front of the Osirion location. SeisImager Software was used for the processing and interpretation of the outcomes. The results were the travel time–distance curves, which were used for building the 2D seismic models that exhibited the velocity and the depth of the layered models. These models were validated by our previous works using electric resistivity tomography and borehole data. The results indicated that this site consisted of three geoseismic subsurface layers. The first layer was the surface that was made up of wadi deposits, which were a mixture of gravel, sand, and silt and were characterized by incompetent to slightly competent materials. The second layer corresponded to the sand and muddy sand deposits of competent rock that was of fair to moderate quality. The third layer (clay deposits) had a higher velocity and was more compact and may be employed as a bedrock layer. The elastic moduli, Vs30, petrophysical, and geotechnical properties of the three geoseismic layers were appraised as essential parameters. Integration of petrophysical and geotechnical parameters and elastic moduli revealed that the third layer was composed of competent clays, which were characterized by low values of porosity, void ratio, Poisson ratio, and stress ratio. It also had a high rigidity, Young’s and bulk moduli, concentration and material indexes, N-value, ultimate bearing capacities, and high density values, and vice versa for the first layer. The standard NEHRP site class was B (rocks). These parameters are ordinarily used as key indications and serve as significant inputs for any future work

An Integrated Geophysics and Isotope Geochemistry to Unveil the Groundwater Paleochannel in Abydos Historical Site, Egypt

The scientific controversy among archaeologists about the existence of paleochannels under the Abydos archaeological site, Sohag, Egypt connecting the Osirion (cenotaph of Seti I) with the Nile River has been explained in this study. This study is an attempt to address this issue using integrating a near-surface geophysical approach with stable isotopic geochemistry on this site. Particularly, the stable oxygen and hydrogen isotopes on the water samples collected from the surface and the groundwater in the study area were analyzed and interpreted. The isotopes result showed that the Osirion water is a mixture of three different types of water: Old Nile Water (ONW) before the construction of the High Dam, Recent Nile Water (RNW) after the construction of the High Dam, and Paleowater (PW) from deeper aquifers. Field observations of the Osirion and nearby water cannot explain the presence and direction of this water. Therefore, the next step in this study is determining the location and the direction of the paleochannel connecting the Osirion with the Nile River which was proven using the electric resistivity tomography (ERT) technique. By using the results of the isotope of all types of water near the Osirion and its surrounding wells and the water of the Nile River, in addition to the near-surface geophysical measurements, the results indicated that the 3D view of the ERT data revealed a prospective paleochannel in the direction of the northeast and its location, where this channel is in charge of providing groundwater from the Nile River to the Osirion location

Simulation of Biophysicochemical Characteristics of the Soils Using Geoelectrical Measurements near the Sewage Station, Assiut City, Egypt

Numerous farmers regularly irrigate their farms with inadequately treated sewage water pumped from the sewage system in the Arab El-Madabegh district of Assiut City, Egypt. According to previous studies, long-term irrigation with partially treated sewage water resulted in significant changes in the physicochemical properties of soil. The principal goals of this study are (1) to infer empirical equations between geoelectrical resistivity measurements and certain biophysicochemical parameters of some soil samples, and (2) to use these empirical equations to calculate the biophysicochemical parameters of the unknown samples for the same location. For this purpose, 27 soil samples at different depth levels (0 to 25, 25 to 60, and 60 to 90 cm) were collected from eleven locations at the sewage station. Physical properties including water content and particle size distribution, chemical properties including soil pH, electrical conductivity (EC), and the heavy metals concentrations, biological properties including total coliform counts, and geoelectrical resistivity measurements were estimated and analyzed for these samples. Electrical resistivity measurements and biophysicochemical properties were cross-correlated using the exponential trend line to fit the cross-correlated data, and the empirical relationships were obtained. These empirical relationships in conjunction with the measured electrical resistivity measurements were used to calculate the biophysicochemical values of the other three random soil samples. The biophysicochemical values of the former three samples were measured by the same normal procedures as 27 samples. Then, the calculated values were correlated with the measured ones. Good correlations between the estimated and the measured values for biophysicochemical features were obtained. Therefore, this method can be employed to calculate the biophysicochemical parameters for any unknown samples that have the same geological conditions for estimating and monitoring soil contamination