Sedimentary cover and structural trends affecting the groundwater flow in the Nubian Sandstone Aquifer System: Inferences from geophysical, field and geochemical data

This study combined gravity data from the Earth Gravitational Model (EGM2008) with other data to better understand the spatial variations of the sedimentary cover and the structural trends that affect groundwater flow in the Nubian Sandstone Aquifer System. Our findings were verified and evidenced by geological, geochronological, geochemical data, and earthquake records: 1) The Uweinat-Aswan basement uplift, which runs east-west, partially isolates the Dakhla subbasin from the shallower northern Sudan subbasin, and thereby impeding the south-to-north groundwater flow from northern Sudan platform to the Dakhla subbasin; 2) A thickening of the sedimentary cover in the NE-SW direction from the southern Kufra through the northern Kufra to the Dakhla subbasin; 3) The sedimentary cover was found to increase from less than 500 m in the south (Northern Sudan and Uweinat region) to more than 6 km in the north (Mediterranean coast); 4) A number of structural trends (NE-SW, N-S, E-W, and NW-SE) affecting the region; 5) A large Pelusium megashear system that runs northeast to southwest makes it easier for groundwater to flow from the Kufra subbasin to the Dakhla subbasin; 6) Along the paths that groundwater takes, like from Siwa to Qattara and from northwest Farafra to north Bahariya, and along structures that run in the same direction as the flow, a progressive increase in 36Cl groundwater ages were observed; 7) It is a better way to learn about the hydrogeological context of large aquifers and figure out how to best manage these underground water sources

Application of GIS-based machine learning algorithms for prediction of irrigational groundwater quality indices

Agriculture is considered one of the primary elements for socioeconomic stability in most parts of Sudan. Consequently, the irrigation water should be properly managed to achieve sustainable crop yield and soil fertility. This research aims to predict the irrigation indices of sodium adsorption ratio (SAR), sodium percentage (Na%), permeability index (PI), and potential salinity (PS) using innovative machine learning (ML) techniques, including K-nearest neighbor (KNN), random forest (RF), support vector regression (SVR), and Gaussian process regression (GPR). Thirty-seven groundwater samples are collected and analyzed for twelve physiochemical parameters (TDS, pH, EC, TH, Ca+2, Mg+2, Na+, HCO3−, Cl, SO4−2, and NO3−) to assess the hydrochemical characteristics of groundwater and its suitability for irrigation purposes. The primary investigation indicated that the samples are dominated by Ca-Mg-HCO3 and Na-HCO3 water types resulted from groundwater recharge and ion exchange reactions. The observed irrigation indices of SAR, Na%, PI, and PS showed average values of 7, 42.5%, 64.7%, and 0.5, respectively. The ML modeling is based on the ion’s concentration as input and the observed values of the indices as output. The data is divided into two sets for training (70%) and validation (30%), and the models are validated using a 10-fold cross-validation technique. The models are tested with three statistical criteria, including mean square error (MSE), root means square error (RMSE), and correlation coefficient (R2). The SVR algorithm showed the best performance in predicting the irrigation indices, with the lowest RMSE value of 1.45 for SAR. The RMSE values for the other indices, Na%, PI, and PS, were 6.70, 7.10, and 0.55, respectively. The models were applied to digital predictive data in the Nile River area of Khartoum state, and the uncertainty of the maps was estimated by running the models 10 times iteratively. The standard deviation maps were generated to assess the model’s sensitivity to the data, and the uncertainty of the model can be used to identify areas where a denser sampling is needed to improve the accuracy of the irrigation indices estimates

Effectiveness of bank filtration for water supply in arid climates: a case study in Egypt

In many developing countries, water demand is increasing while surface- and groundwater resources are threatened by pollution and overexploitation. Hence, a more sustainable approach to water resources management and water treatment is required. In this capacity, bank filtration is a natural treatment process that makes use of the storage and contaminant attenuation capacity of natural soil. However, BF is site-specific and a significant knowledge gap exists regarding the design and management of bank filtration systems, particularly in developing countries. This research aimed to address these gaps and contribute to the transfer of bank filtration to developing countries. This study comprised both column and batch laboratory-scale experiments to determine the effect of environmental variables such as temperature, raw water organic composition and redox conditions on the removal of chemical pollutants such as organic matter, micro-pollutants and heavy metals as well as the mobility of iron, manganese and arsenic under anaerobic conditions. Ultimately, the effectiveness of BF in improving the quality of drinking water was assessed in a case study in Egypt. The study showed that more than 80% of biodegradable organic matter was removed during BF at temperatures between 20 and 30 °C. However, post-treatment is required to remove humic compounds that were enriched during infiltration. Moreover, infiltrating water with a high concentration of humic compounds reduced the removal of heavy metals and promoted the release of metals into the infiltrating water, rendering it more feasible to install BF wells in surface water systems with low levels of organic matter. Moderately hydrophobic organic micropollutants were most persistent and required infiltration times in excess of 30 days for complete elimination, even at high temperatures (>20 °C). Finally, design parameters such as the number of infiltration wells, should be configured to minimise the proportion of polluted groundwater in the pumped water. Overall, this study provides insight into the effectiveness of BF in removing chemical pollutants from surface water and proposes guidelines for the successful application of BF in developing countries where arid conditions and high temperatures prevail.Dissertation submitted in fulfillment of the requirements of the Board for Doctorates of Delft University of Technology and of the Academic Board of IHE Delft Institute for Water Education.Water ResourcesSanitary Engineerin

Effectiveness of bank filtration for water supply in arid climates : A case study in Egypt

In many developing countries, water demand is increasing while surface- and groundwater resources are threatened by pollution and overexploitation. Hence, a more sustainable approach to water resources management and water treatment is required. In this capacity, bank filtration is a natural treatment process that makes use of the storage and contaminant attenuation capacity of natural soil. However, BF is site-specific and a significant knowledge gap exists regarding the design and management of bank filtration systems, particularly in developing countries. This research aimed to address these gaps and contribute to the transfer of bank filtration to developing countries. This study comprised both column and batch laboratory-scale experiments to determine the effect of environmental variables such as temperature, raw water organic composition and redox conditions on the removal of chemical pollutants such as organic matter, micro-pollutants and heavy metals as well as the mobility of iron, manganese and arsenic under anaerobic conditions. Ultimately, the effectiveness of BF in improving the quality of drinking water was assessed in a case study in Egypt. The study showed that more than 80% of biodegradable organic matter was removed during BF at temperatures between 20 and 30 °C. However, post-treatment is required to remove humic compounds that were enriched during infiltration. Moreover, infiltrating water with a high concentration of humic compounds reduced the removal of heavy metals and promoted the release of metals into the infiltrating water, rendering it more feasible to install BF wells in surface water systems with low levels of organic matter. Moderately hydrophobic organic micropollutants were most persistent and required infiltration times in excess of 30 days for complete elimination, even at high temperatures (>20 °C). Finally, design parameters such as the number of infiltration wells, should be configured to minimise the proportion of polluted groundwater in the pumped water. Overall, this study provides insight into the effectiveness of BF in removing chemical pollutants from surface water and proposes guidelines for the successful application of BF in developing countries where arid conditions and high temperatures prevail

Unusual form of Mullerian Agenesis Syndrome

A rare case of Mayer-Rokitansky-Kuster-Hauser syndrome is reported. A 24 year old, Egyptian female with primary amenorrhea, primary infertility since 24 months, and difficulty in sexual intercourse with a male partner. She is phenotypically female – has well devolped female secondary sexual characteristics – and has normal female external genitalia. There is a shallow vaginal dimple. Absence of the upper vagina and two uterine buds separate from each other demonstrated by MRI and laparoscopy. Ultrasound and intravenous pyelography have documented no renal anomalies. Chromosomal analysis reveals a normal female karyotype (46, XX). Endocrine evaluation shows normal levels of estradiol, follicle-stimulating hormone and luteinizing hormone. Radiographs did not reveal any associated skeletal abnormalities. Aside from this being a rare case of a disorder of sexual development, this is worth reporting because it illustrates the diagnostic work-up of a patient presenting with primary amenorrhea

Hydro-Geophysical Evaluation of the Regional Variability of Senegal’s Terrestrial Water Storage Using Time-Variable Gravity Data

The Gravity Recovery and Climate Experiment (GRACE) satellite data retrieval experiment has been instrumental in characterizing the global fluctuations in terrestrial water storage (ΔTWS) over the past 20 years. Given the limited availability of hydrological data, GRACE measurements are frequently combined with other climatic models, standardized precipitation index (SPI), and standardized temperature index (STI) data to examine the likelihood of such impacts on hydrology and calculate the groundwater storage changes (ΔGWS). The characterization of the intensity and variability of drought events has been identified based on the Terrestrial Water Storage Deficit Index (TWSI), derived from GRACE mass concentration blocks (mascons) over Senegal during the studied period (April 2002–December 2021). The results are: (1) The average annual precipitation (AAP) rate for the entire period was calculated at 692.5 mm/yr. (2) The GRACE-derived ΔTWS variations were calculated at +0.89 ± 0.34, +0.07 ± 0.36, +1.66 ± 1.20, and +0.63 ± 0.08 cm/yr for Periods I (April 2002–December 2009), II (January 2010–December 2017), III (January 2018–December 2021), and the entire period (April 2002–December 2021), respectively. (3) The ΔGWS changes were estimated to be +0.89 ± 0.31, +0.085 ± 0.33, +1.64 ± 1.11, and +0.63 ± 0.08 cm/yr for Periods I, II, II, and the entire period, respectively. (4) There is good agreement in some years and seasons according to the investigation of the link between the GRACE dataset, STI, and SPI. (5) Senegal’s groundwater storage is increasing at a rate of 0.63 ± 0.08 cm/yr (1.24 ± 0.16 km3/yr) between April 2002 and December 2021. (6) Considering the yearly extraction rates of 1.13 ± 0.11 cm/yr (2.22 ± 0.22 km3/yr), an average recharge rate of +1.76 ± 0.14 cm/yr (+3.46 ± 0.28 km3/yr) was calculated for the studied area. The integrated strategy is instructive and economical

Detection of Mineralization Zones Using Aeromagnetic Data

Every day, mining corporations grow and develop over Egypt’s Eastern Desert in search of gold, silver, and other metals. Mineral resources in Egypt are a powerful tool for increasing national income. In this study, we are interested in mineral exploration, such as gold and porphyry deposits, using aeromagnetic data, applying various processing techniques such as First Vertical Derivative, Total Horizontal Gradient, Analytical Signal, Tilt Derivative, and the center of exploration targeting. The study area is located at the Central Eastern Desert, which includes the Barramiya, Abu Marwa, and Abu Mireiwah regions. The analysis of the delineated structural trends shows that the N–S, NW–SE, and NE–SW are the most effective directions for managing deposits in the investigated area. A minor trend is also shown in the E–W direction and corresponds to the alteration zones reported by geology and prior investigations. Mineralization zones occur most frequently at the contact between ophiolitic serpentinite, sediments, and other rock types. This study intends to add more about the use of the recently developed technology of CET grid analysis for mineral exploration and structural interpretation across the Central Eastern Desert. The CET porphyry analysis map shows locations where several occurrences of porphyry deposits are probable. The newly discovered spots are similar to the area’s usual deposit sites. This study proves that aeromagnetic data are significant in mineral exploration since they are useful for the discovery of the structure and shear zones controlling the mineralization zones.Water Resource

Impact of green roofs on energy demand for cooling in Egyptian buildings

Energy consumption for cooling purposes has increased significantly in recent years, mainly due to population growth, urbanization, and climate change consequences. The situation can be mitigated by passive climate solutions to reduce energy consumption in buildings. This study investigated the effectiveness of the green roof concept in reducing energy demand for cooling in different climatic regions. The impact of several types of green roofing of varying thermal conductivity and soil depth on energy consumption for cooling school buildings in Egypt was examined. In a co-simulation approach, the efficiency of the proposed green roof types was evaluated using the Design-Builder software, and a cost analysis was performed for the best options. The results showed that the proposed green roof types saved between 31.61 and 39.74% of energy, on average. A green roof featuring a roof soil depth of 0.1 m and 0.9 W/m-K thermal conductivity exhibited higher efficiency in reducing energy than the other options tested. The decrease in air temperature due to green roofs in hot arid areas, which exceeded an average of 4 °C, was greater than that in other regions that were not as hot. In conclusion, green roofs were shown to be efficient in reducing energy consumption as compared with traditional roofs, especially in hot arid climates.Water ResourcesSanitary Engineerin

Monitoring Mass Variations in Iraq Using Time-Variable Gravity Data

Iraq is facing a water shortage due to water scarcity and anthropogenic activities. The recent advance in technologies in geophysical methods has made groundwater monitoring possible. Time-variable gravity data and outputs of the climatic model, as well as rainfall data, are integrated to investigate the spatio-temporal mass variations caused by groundwater changes over Iraq. The findings are: (1) For the entire study period (04/2002–12/2020), Period I (04/2002–12/2006), Period II (01/2007–12/2017), and Period III (01/2018–12/2020), the study region had an average annual precipitation rate of 223.4, 252.5, 194.2, and 311.6 mm/y, respectively. (2) The average Terrestrial Water Storage variations (ΔTWSs) varied from −5.79 ± 0.70 to −5.11 ± 0.70 mm/y based on the three different gravity solutions with a mean of −5.51 ± 0.68 mm/y for the entire investigated period. (3) For Periods I, II, and III, the average ΔTWS fluctuation was calculated to be +6.82 ± 1.92, −6.20 ± 1.17, and +28.58 ± 12.78 mm/y, respectively. (4) During the entire period, Periods I, II, and II, the groundwater fluctuation was averaged at −4.86 ± 0.68, +2.47 ± 2.20, −3.79 ± 1.20, and −4.63 ± 12.99 mm/y, respectively, after subtracting the non-groundwater components. (5) At the beginning of the 2007 drought during Period II, a decline in rainfall rate, and significant groundwater withdrawal during Period III all appear to have contributed to groundwater depletion. The Euphrates and Tigris Rivers, as well as the Mesopotamian plain, receive water from the running streams created by the ground relief. The area of the Mesopotamian plain, which has a thicker sedimentary sequence that can reach 9000 m, is found to have a positive TWS signal, indicating that its groundwater potential is higher. The integrated approach is informative and cost-effective.Water Resource

Integrated Geophysical Approach of Groundwater Potential in Wadi Ranyah, Saudi Arabia, Using Gravity, Electrical Resistivity, and Remote-Sensing Techniques

In order to cope with the rise in human-caused demands, Saudi Arabia is exploring new groundwater sources. The groundwater potential of Wadi Ranyah was studied using a multi-dataset-integrated approach that included time-variable gravity data from the Gravity Recovery and Climate Experiment (GRACE), vertical electrical sounding (VES), and time-domain-electromagnetic (TDEM) data with other related datasets to examine the variations and occurrence of groundwater storage and to define the controlling factors affecting the groundwater potential in Wadi Ranyah in southwestern Saudi Arabia. Between April 2002 and December 2021, the estimated variation in groundwater resources was −3.85 ± 0.15 mm/yr. From 2002 to 2019, the area observed an average yearly precipitation rate of 100 mm. The sedimentary succession and the underlying fractured basement rocks are influenced by the structural patterns that run mainly in three different trends (NW, NE, and NS). The sedimentary cover varies from 0 to 27 m in thickness. The outputs of the electrical sounding revealed four primary geoelectric units in the study area: on top, a highly resistant geoelectrical unit with a resistivity of 235–1020 Ω.m, composed of unsorted, loose, recent sediments; this is followed by a layer of gravel and coarse-grained sands with a resistivity of 225–980 Ω.m; then, a water-bearing unit of saturated sediments and weathered, fractured, basement crystalline rocks with a resistivity of 40–105 Ω.m, its depth varying from 4 to ~9 m; and then the lowest fourth unit composed of massive basement rocks with higher resistivity values varying from 4780 to 7850 Ω.m. The seven built dams store surface-water runoff in the southwestern part of the wadi, close to the upstream section, in addition to the Ranyah dam, as the eighth one is located in the middle of the wadi. The subsurface NW- and NS-trending fault lines impede the groundwater from flowing downstream of the wadi, forming isolated water-bearing grabens. Minimal surface runoff might occur in the northern part of the wadi. The combined findings are beneficial because they provide a complete picture of the groundwater potential of Wadi Ranyah and the controlling structural patterns. Using this integrated technique, the groundwater potential in arid and semiarid regions can now be accurately assessed