El-Dakhla Oasis Research Articles

Natural radiological risk assessment around archaeological sites, El-Dakhla Oasis (EDO), Egypt

The natural radionuclides in ancient El-Qasr village located in the El-Dakhla oasis (EDO), Egypt's Western Desert were measured using gamma-ray spectrometry equipped with a NaI (Tl) detector. The findings indicate that the samples' mean activity concentrations were 18.61 ± 1.02, 16.67 ± 0.9, and 137.67 ± 6.9 Bq kg−1 for 226Ra, 232Th, and 40K, respectively. The values of Raeq, D, AED, Hex, Hin, Iγ, and ELCR for the samples ranged anywhere from 34.1 to 83.9 Bq kg−1, 15.7 to 37 nGy h−1, 19.26 to 45.384 Sv y−1, 0.09 to 0.23, 0.12 to 0.23, 0.25 to 0.59, and 6.74E−05 to 1.59E−04, respectively. These values are significantly lower than the international limit of 370 Bq kg−1 for Raeq, 59 nGy h−1 for D, 70 Sv y−1 for AED, 1 for Hex and Hin, 2 for Iγ, and 29E−03 for ELCR. According to the obtained data, none of the samples seemed to be a significant risk when it came to radiation exposure. Using these data, we will determine the baseline level of radionuclides that occur naturally in the area that is the subject of the inquiry.

Soil quality and land capability evaluation for agriculture in Balat area, El Dakhla Oasis, western Desert, Egypt

This research aimed to evaluate the land capability and soil health of the Balat area, El-Dakhla Oasis, Egypt. To achieve this objective, thirty soil profiles were chosen to represent the study area and soil samples were collected from each layer of each soil profile. Soil samples were analyzed for their physical, chemical, and fertility properties. These soils were characterized and classified. The obtained results were mapped for spatial variability distribution using ArcGIS software. The land capability was evaluated using the modified Storie index and the Microcomputer Land Elevation Information system (MicroLEIS). The soil quality index (SQI) was also calculated based on soil physical, chemical, and fertility indices. The obtained results revealed that the studied soils were alkaline, slightly saline to moderately saline, light to heavy textured, non-calcareous to calcareous, and poor in organic matter and nutrients. These soils were classified into two orders (Entisols and Aridisols), whereas they were found in three subgroups (Typic Torripsamments, Typic Torriorthents, and Typic Haplosalids). The modified Storie index was found to be better than the MicroLEIS Cervatana model in evaluating land capability. Four land capability grades were obtained from the Storie index (Grade 2 = Good; Grade 3 = Fair; Grade 4 = Poor; and Grade 5 = Non-agricultural), while two grades were recorded in MicroLEIS (S3 and N). The main limitations of the study area were soil texture, salinity, organic matter, and ESP. Regarding the soil quality, two grades were obtained from the applied method (moderate = 0.35–0.59 and good = 0.60–0.79). Spatial variability maps were generated for land capability methods as well as the soil quality. Therefore, these results and maps can be utilized as a guide for better planning and land resource management in the Balat area.

Assessment of Soil Spatial Variability for Agricultural Potential in El-Dakhla Oasis, New Valley, Egypt.

Assessment of Soil Spatial Variability for Agricultural Potential in El-Dakhla Oasis, New Valley, Egypt.

Effect of Pollination Time and Hours of Day Time on Fruit Set and Production of Seewy Date Palm cultivar in El Dakhla Oasis New Valley Governorate.

Effect of Pollination Time and Hours of Day Time on Fruit Set and Production of Seewy Date Palm cultivar in El Dakhla Oasis New Valley Governorate.

Heterorhabditis brevicaudis: A New Nematode Species Isolated from El-Dakhla Oasis in Egypt and Its Efficiency against Some Lepidopteran Pests

Background: Entomopathogenic nematodes have been used as biopesticides for controlling insect pests in niche markets. Many new isolates have been recovered from soil of natural habitats in many parts of the world. Native EPNs may be more suitable for controlling local pests. Therefore, isolation and identification of native nematode-bacterial associations are necessary for the successful control of endemic pests. Methods: The occurrence of an EPN, Heterorhabditis brevicaudis and its symbiotic bacteria was newly isolated from Egypt and recorded for the first time in this report. Diagnosis was based on morphometric characteristics and cross-hyperdization. Biochemical characterization and antibiotic activity of its bacteria were investigated. The new species activity was studied against four lepidopteran pests under laboratory conditions. Results: The isolate was proved to be a new species and was congruently belongs to H. brevicadus. The bacteria produced very strong bioluminescence and its antimicrobial activity is of medium level. H. brevicaudis was highly pathogenic to G. mellonella; T. absoluta and A. ipsilon larvae when mature larvae were treated with doses of 150, 100, and 50 IJs/ml, respectively. Conclusion: This is the first report of H. brevicaudis from Egypt. Data showed that the isolate is a new heterorhabtid species. Its symbiotic bacteria belong to ideal criteria and parameters that support nematode growth and pathogenicity. The antibiotics production is an advantage for the successful culturing of EPNs. This new EPN had a good impact against the four tested economic insect pests and could be positively enrolled in an integrated pest management program.

Geomatics-Based Modeling and Hydrochemical Analysis for Groundwater Quality Mapping in the Egyptian Western Desert: A Case Study of El-Dakhla Oasis

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.

Damage of the Egyptian Fruit Bat (Rousettus aegyptiacus) at El-Dakhla Oasis, New-Valley Governorate, Egypt

Background: The Egyption fruit bat, Rousettus aegyptiacus, is considered a harmful pest that attacks agricultural crops, especially ripe fruits, causing economic losses. It is widespread in African sahara desert, Egypt, Pakistan and Northern India. This pest causes damage to many vegetables and fruits. The measuring of damage percentage will aid in the protection of these crops from bats attacking. Methods: The losses caused by Egyptian bats were estimated during two years (2019 and 2020) in many fruit orchards (date palm, citrus, apricot and mango) in reclaimed lands at Butt village, Dakhla Oasis, New-valley Governorate, to achieve integrated management of bat populations. Result: Only one species the Egyptian fruit bat, R. aegyptiacus, has been recorded with 167 individuals attacking fruit orchards. The highest average losses (11.1%) were found in date palms, from August to Oct., while the lowest (4.7%) were found in Apricot, during June and July. The second-highest losses were 7.6% in mango from June to August. The damage began from December to March in citrus with an average loss percent of 7.0%. Therefore, bat dens must be monitored and dealt with to limit their populations and reduce their losses to these value crops in El-Dakhla Oasis.

Conservation of Earth Vernacular Settlements. A Case Study of El-Dakhla Oasis, Egypt

Conservation of Earth Vernacular Settlements. A Case Study of El-Dakhla Oasis, Egypt

Diagnosis of Fasciola spp. infection in cattle in El-Dakhla Oasis, Egypt by Intradermal test and Enzyme-Linked Immunosorbent Assay

Diagnosis of Fasciola spp. infection in cattle in El-Dakhla Oasis, Egypt by Intradermal test and Enzyme-Linked Immunosorbent Assay

Innovating new methods for wastewater treatment in El-Dakhla Oasis in Upper Egypt from chemical and biological pollutants using modified Down Flow Hanging Sponge (DHS) reactor in presence of new environmental friendly chelator

Modified Down Flow Hanging Sponge (DHS) reactor will be a smart water treatment technology in the near future. It has advantages like low cost, ease of use and satisfaction level. One of the major geoenviromental problems in El-Dakhla region arises from the hazards exploitation of groundwater resources and sewage dumping which have resulted in waste water accumulation in the form of ponds. The most common pollutants are heavy metals, organic residue and microbes. The reactor was used for excellent removal of notorious heavy metals, organic pollutants and harmful microbes. In order to achieve these objectives, treatment scheme has been investigated. It consists of mixing new organic chelator with wastewater in different concentrations followed by a Down Flow Hanging Sponge (DHS) reactor. The residual values of heavy metals were (Mn) amount decreased from 1.00 ppm to zero ppm (100%) after 60 min.,(Fe) decreases from 0.997 ppm to zero ppm (100%) after 60 min. (Cd) decreased from 0.901 ppm to zero ppm (100%) after 60 min. (Cu) decreased from 1.1 ppm to zero ppm (100%) after 60 min. (Pb) decreases from 1.004 ppm to zero ppm (100%) after 60 min. (Ni) decreased from 0.922 ppm to 0 ppm (100%) after 60 min. The results show that removals of fecal coliforms were achieved. From the results of DHS effluent, fecal coliforms decreased from 5.2x106 to 200 and the overall removal efficiency of fecal coliforms was (99.99%) at 37Co.

Genetic variation within and among the wild populations of Alhagi graecorum using ISSR markers

Abstract: Alhagi graecorum Boiss. (Camel thorn) (Family Fabaceae) is a wild plant which grows in salty soils and dry environment. It is native to Mediterranean and central Asia. Several studies have revealed the use of Alhagi plants in treating a wide spectrum of diseases. In this study, eight ISSR primers were used to assess genetic diversity of five populations of A. graecorum (El-Dakhla Oasis; Botanical garden of botany department, Ain Shams University; Wadi El-Rayan; Qarun Lake and Siwa Oasis) using individual- and bulked samples based approaches. Twenty five individuals were sampled, amplified separately and amplified as bulked DNA to identify polymorphism among the studied populations. In total, 101 and 97 bands were scored with 83.3% and 78.4% polymorphism, respectively. Average polymorphism information content (PIC) for amplified DNA of individual samples was 0.875 and bulked-samples was recorded 0.69. Analysis of molecular variance (AMOVA) showed that 63% of the total variation was observed among populations while variation within populations accounted for the remaining 37%. The highest genetic similarity index was (0.99) among the studied Alhagi genotypes was recorded between the two genotypes 6 and 7 both individuals were belonging to Ain Shams University population, while among inter populations was (0.853%) between Qarun Lake and Siwa Oasis populations. The UPGMA cluster analysis divided the 25 individuals and bulked samples into two main groups. Each group was further subdivided into many sub-clusters, PCoA was also carried out and in agreement with the UPGMA. The obtained results demonstrate that the ISSR markers were efficient for evaluation of the genetic relationships between intra- and inter-population due to their efficiency in revealing polymorphism.

Exploratory Properties and Restrictions of El-Zayat Soils for Agricultural Sustainability, El-Dakhla Oasis, Egypt

Exploratory Properties and Restrictions of El-Zayat Soils for Agricultural Sustainability, El-Dakhla Oasis, Egypt

Soil Salinity Impact on Phosphorus Forms of Some Soils of El-Dakhla Oasis, Egypt

Soil Salinity Impact on Phosphorus Forms of Some Soils of El-Dakhla Oasis, Egypt

Salinity Status of Groundwater in El-Dakhla Oasis, New Valley Governorate, Egypt

Salinity Status of Groundwater in El-Dakhla Oasis, New Valley Governorate, Egypt

Evaluation of Potassium Quantity-Intensity in some Soils of El-Dakhla Oasis, New Valley, Egypt

Evaluation of Potassium Quantity-Intensity in some Soils of El-Dakhla Oasis, New Valley, Egypt

Potassium Forms of EL-Dakhla Oasis Soils, New Valley Governorate, Egypt

Potassium Forms of EL-Dakhla Oasis Soils, New Valley Governorate, Egypt

Available Phosphorus Assessment of Gharb El-Mawhoob Soils, El-Dakhla Oasis, Egypt

Available Phosphorus Assessment of Gharb El-Mawhoob Soils, El-Dakhla Oasis, Egypt

Evaluation Of Present-Day Climate-Induced Desertification In El-Dakhla Oasis, Western Desert Of Egypt, Based On Integration Of MEDALUS Method, GIS And RS Techniques.

Abstract Limited to fourth percent or less of the country’s total land area, Egypt’s agricultural landscape is threatened by the repercussions of climate change, desertification, soil depletion, and looming water scarcity. Outside of the Nile river valley and scattered fertile pockets in the desert oases, the vast majority of land is desert: rocky, parched and unable to support conventional farming. According to Egyptian National Action Program 2005 (ENAP), Egypt covers an area of about one million km2 ~ 100 million hectares, out of which about of 76.5 thousands km2 ~ 7.6% of the total area are inhabited, and the remaining (92.4%) area is desert. Desertification is a very complex process governed by several variables which influence each other. It is thus not possible to conclude for the general picture from a single factor alone. This process has a high rate in arid and hyper-arid countries such as Egypt. The main objective of this research was to evaluation the present-day climate-induced desertification in El-Dakhla Oasis, so in this study, the newest method for evaluating and mapping of desertification was used. The mathematic method was carried out by European Commission (EC), (MEditerranean Desertification And Land Use) at the MEDALUS project and booked as ESAs in 1999 integrated with remote sensing and GIS. All indices of the model were revised before using, and regarding to the region condition these indices were defined as key indices which were: Temperature, precipitation, wind, albedo, ground water and soil benchmark, and each benchmark has some sub-layers getting from their geometric mean. Based on the MEDALUS model, each sub-benchmark was quantified according to its quality and given a weighting of between 1.0 and 2.0. All benchmarks should be reinvestigated and adjusted to local conditions. Ultimately, desertification severity was classified in four level including low, moderate, Severe and high Severe. ArcGIS 10 was used to analysis and prepares the layers of quality maps using the geometric mean to integrate the individual sub-indicator maps. In turn the geometric mean of six quality maps was used to generate a single desertification status map. Remote sensing data have great potential to improve models mapping spatial variability of temperature and precipitation since they are available as time worldwide, and have high spatial resolution. The HYDRA visualization software was used to measure the present surface albedo from MODIS product (MOD43C1). Results showed that 60% of the area is classified as Severe, 14 % as moderate and 12%, 16% as low and none affected by desertification respectively. In addition the climatic variations including rainfall, temperature, sunlight, wind indicators were the most important factors affecting desertification process in El-Dakhla Oasis.

Subsurface tectonic pattern and basement topography as interpreted from aeromagnetic data to the south of El-Dakhla Oasis, western desert, Egypt

The study area lies to the south of El-Dakhla Oasis in the central part of the western desert, Egypt. It is limited by the latitudes 24–25° N and the longitudes 28–30° E. The main purpose of this work is the investigation of the subsurface structure and the delineation of the main structural elements at different subsurface levels. This study aims also to estimate the basement depth, the basement relief, and consequently, the thickness of the sedimentary cover. The study is based on acquired aeromagnetic data prepared by "La Compagnie General De Geophysique" for the Egyptian General Petroleum Company and Conoco (1977), geological information and results of previous studies in the region. The study involves the analysis for the aeromagnetic data and generating of reduced to pole magnetic map from which different magnetic maps are calculated. The calculated maps are first vertical derivative map and downward continuation map at depth level 400 m. Trend analysis technique is used to define the fault pattern affecting the studied area at different subsurface levels. It is applied to the reduced to pole magnetic map, the first vertical derivative map, and the downward continuation map at depth level 400 m of the study area. All results obtained from the interpretation process were combined together to draw the general view of the subsurface structures of the area. The NE–SW, E–W, and N–S trends are important surface and subsurface (basement) structural trends. This is attributed to the rejuvenation of movements on these old (basement) tectonic trends after the deposition of the sedimentary cover. Basement depth calculation from the aeromagnetic data is achieved using different techniques. The applied techniques included natural spectral analysis and Euler deconvolution. The depth values obtained vary from 400 to 1,700 m.

Investigating traditional natural ventilation methods used in El-Dakhla Oasis, old village

Several natural ventilation techniques are employed in traditional desert architecture across the hot-dry region. These techniques vary depending on the socio-climatic requirements of the communities. This article presents the results of a field study investigating the natural ventilation techniques used in a traditional Sahara desert village called El-Qasr located in El-Dakhla Oasis in Egypt. The study investigates the drivers of the natural ventilation systems used. It was found that the main drivers of natural ventilation in El-Qasr are: street canyon design; street and building wind orientation; building form and spatial planning; and opening design.