Sahara Of Algeria Research Articles

The evolution of agricultural areas in a Saharan region by satellite imagery (landsat, sentinel) case of the Oued Righ region, Algeria

During this study, our objective was to systematically identify predominant spatiotemporal trends related to the evolution of agricultural perimeters in a Saharan region, specifically the oases of Oued Righ in Algeria. To achieve this, we used satellite imagery data. The chronological sequence of satellite images covering the Oued Righ region, situated in the Northeastern Sahara of Algeria, was meticulously established. Spatial remote sensing proved to be an essential tool, providing us with up-to-date and geo-referenced data regarding vegetation. We used a time series of Landsat (8, 4-5, 7) and Sentinel 2 images covering Oued Righ from 1984 to 2024, using bands 4, 3, 2, and 5, 4, 3 infrared. These images offered precise insights into the actual vegetation development in the study area, eliminating any guesswork. Our analysis relied on vegetation indices, notably the NDVI (Normalized Difference Vegetation Index), allowing us to objectively and scientifically monitor the evolution of this perimeter.

Performance analysis of biochar and W. Robusta palm waste reinforced green mortar using response surface methodology and machine learning methods

The pressing issue of growing carbon dioxide (CO2) levels and global warming has prompted efforts to create new building materials with the capacity to absorb and store CO2. Using cement substitutes helps to preserve the environment by slowing the spread of carbon dioxide. As a result of the abundance of Washingtonia robusta waste (WRW) produced during maintenance operations on Washingtonia robusta (WR) and sand from the dunes of Algeria's Sahara desert, as well as the production of biochar made from a pyrolysis at 500°C of these residues (WRWB) on the flexural, compressive properties and porosity of cementitious mortars are explored. The approach is based on gradually replacing cement with WFRB biochar and WRW fibre waste at varying rates: from 0 % to 2 % with a step of 0.5 % and treated for different periods of time (24, 72, and 168 hours) at different NaHCO3 concentrations (4, 8 and 16 %). According to the response surface method (RSM) and artificial neural networks (ANN), the optimal cement substitution of rates were 1,8 % of WRWB and 1,3 % of WRW treated with 4 % of CaCO3 concentration for a 23,6 hour. Furthermore, it is appropriate to note that predictive accuracy using ANN models is higher than that of RSM models, as demonstrated by their good correlation with developed models' experimental data. These techniques have increased the use of green mortars and their acceptance as construction materials.

Monitoring the spatial evolution of groundwater quality during its diversion in the drinking water supply network in arid areas, case of Bechar city (Algeria Sahara)

Climate change has clearly affected the desert city of Bechar, located in southern Algeria, and this miserable situation for the supply of drinking water prompted the authorities to provide capabilities and funds to bring groundwater located 250 km away and transfer it to the city of Bechar. The characterization of these underground waters presents a bicarbonate-magnesian facies according to the diagram of Schöeller and Berkaloff; the representation of the data on the triangular Piper diagram shows that Boussir ground water has the magnesium bicarbonate facies. The calculation of the quality index (GWQI) shows that all samples taken from the boreholes belong to the good quality category. The long distance of diversion of this underground water and the quality of the materials used in the project under a dry desert climate made us carry out the process of monitoring and tracking the quality of the water from the well until it reaches the consumer. The results revealed that all the levels of the physic-chemical parameters do not exceed the WHO portability standards, except that a variation of certain values was observed at the level of the storage tank, this variation due to the mode of filling and the mixing of water in tubular form, without eliminating the effect of water stagnation. If we technically know how to produce high-quality drinking water, we cannot always ensure a safe and sustainable water supply of the same quality in distribution networks and reservoirs; it is from this principle that our article is based in order to reinforce the monitoring role.

Environmental – Solar thermal effects a long-term on the efficiency of amorphous climate-resilient mortar using a central composite design application

The objective of this investigation is to evaluate the durability of dune sand mortar containing display e-glass waste (DEGW) in severe Saharan environments, chemical attacks, or other factors that can cause cementitious materials to deteriorate at long- term. The aim is to use DEGW powder as a partial replacement for dune sand in various mortar mixtures and assess the performance of hardened mortar in terms of ultrasonic pulse velocity, dynamic elasticity modulus, compressive strength, and flexural strength and sportivity. The study also examines the influence of the curing period and different climatic conditions in curing environments, such as those in Algeria's Sahara region. The Response Surface Methodology (RSM) was used to adjust the e-waste glassy mortar, with the statistical tool Central Composite Design (CCD) approach. The hydration of cement compounds was monitored using differential thermal analysis (DTA), thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), and X-ray diffraction (XRD). The DEGW was replaced in 5% increments from 0% to 20%. The results showed that the glassy dune sand mortar exhibited the highest properties at 20% incorporation after 365 days of severe climatic conditions. The feasibility of the proposed quadratic model was recommended for the five responses by RSM, in which the coefficient of determination (R2) ranges from 0.93 to 0.97, showing the model’s high significance. For structural display e-glassy dune sand mortar, display glass E-waste can replace 20% of dune sand, which improves all durability and environmental sustainability. Furthermore, the DSC, TGA / DTA results and XRD analysis showed that the < 0.08 mm class exhibited good pozzolanic behaviour, and the specimens significantly improved as curing periods increased.

Wild plants diversity in two Wadi beds in the Ouargla region (Northern Sahara of Algeria)

In the Sahara, rangelands, offer favorable conditions for vegetation survival. The present study focused on estimating the diversity and determining the functional traits of spontaneous plants established in two Wadi beds, the Wadi N’Sa bed and the Wadi Mya bed, in the Ouargla region (northern east of the Algerian Sahara). For each Wadi bed, 23 phytosociological surveys were selected to study the diversity parameters, plant functional traits, and soil analyses to study the vegetation–soil relationships.

Spatial distribution of microalgae in the Central Sahara of Algeria: Case of the Hoggar and Tassili cultural parks

The present investigation embarks on understanding the spatial distribution of the microalgae population in the Hoggar and Tassili regions of the Central Sahara of Algeria. Thirty-eight sites were sampled between April 2016 and April 2017. Environmental parameters were measured at each station. A total of 77 taxa belonging to 7 classes were identified: Bacillariophyceae (27), Cyanophyceae (15), Chlorophyceae (14), Zygnematophyceae (13), Euglenophyceae (5), Dinophyceae (2), and Xanthophyceae (1). The highest values of the Shannon-Weaver and Equitability indexes were recorded at station H5S1 (H' = 4.62, E = 0.95), respectively, in the region of Hoggar. In the Tassili region, the highest values were recorded at station T1S2 (H' = 4.50, E = 0.88), respectively. Canonical correspondence analysis (CCA) was established between the environmental parameters and species in both regions. According to the results, pH, altitude, and depth were the most important environmental factors influencing the microalgae diversity.

First study of continental bioerosion traces on vertebrate remains from the Cretaceous of Algeria

Trace fossils, representing ichnospecies Cubiculum ornatus, C. inornatus, Cubiculum isp., and Cuniculichnus variabilis as well as three indeterminate morphological categories (thin branching grooves A and B, furrows and circular chambers), are here recorded on vertebrate remains from the mid-Cretaceous (lower Cenomanian) of the ‘Continental Intercalary’ deposits in the Gara Samani locality (central Sahara of Algeria). Apart from thin branching grooves (A and B), which are thought to result from root etching, the bioerosion traces recorded on the bones comprise circular chambers and furrows, which represent pupation chambers of scavenging insects, most likely attributed to dermestid beetles. These trace fossils are identified and described for the first time from the Cretaceous of Algeria. They add new data to the trace-fossil assemblages previously reported from other Cretaceous successions of North Africa (e.g., the Kem Kem beds in Morocco). Sedimentological clues indicate a braided fluvial system environment. Taphonomic analysis suggests that the vertebrate remains were most likely subaerially exposed for a prolonged time prior to being transported and finally buried. Therefore, most of the studied borings are likely the result of dermestid beetle larvae feeding on dry bones on dry lands; other borings represent plant etchings produced after the bones were partially covered by, or completely buried, in sediments.

Mineralogical and Micromorphological Properties of Oued Righ Region Soils in the Northern Sahara of Algeria

Mineralogical and Micromorphological Properties of Oued Righ Region Soils in the Northern Sahara of Algeria

MORPHO-PEDOLOGY VARIATIONS IN A PRE-SAHARAN REGION CASE ZIBAN SOILS

During this study, we tried to highlight the main lines of the spatial evolution of the morpho-pedological characters of certain soils, on a sequence established from the geomorphological map in the region. Biskra is an Oasis located in the North-Eastern Sahara of Algeria. After a long prospection, we have established two sequences of soils which have different morphological characteristics. These variations are mainly due to the geomorphological position of the terrain and the favorable hydrological aspect in the first sequence to the formation of gypsum soils compared to the second.

Effect of some chemical additives on reducing the permeabilty of agricultural soils and the consumption of irrigation water during the plantation of potatoes 'oued souf'

Agriculture is an important sector in Algeria, it is the second economic component of the country, however the country suffers from water shortage and high soil permeability, especially in the Sahara region The Sahara area in Algeria accounts for about 85% of its total area, the Algeria's Sahara considered as the most arid region in the world and has a high soil permeability, Leading to consume a large quantities of water for irrigation. In order to solve these problems, hydrogels are the effective solution proposed. Hydrogel s have the capacity of holding a large amount of water and keep it c lose to the plant's roots . The purpose of this study was to estimate the effect of hydrogel on soil permeability by application of three different dosage of Hydrogel in three parcels. The results proved that the addition of hydrogel enabled to yield 50% more production, using almost 50% less water.

Chemical composition and biological properties of Cotula cinerea essential oil from Sahara of Algeria

The work focuses on the valorization of the plant Cotula cinerea Del., which grows spontaneously in Algeria. It is collected from two stations in the province of El Oued, to assess the chemical composition of essential oils, from two different zones whereas Beni Guecha is a reg unlike Sidi Aoun is a sandy area characterized by the presence of dunes, and to test biological activities. Oil analysis by CG/MS enabled the identification of 28 terpene components representing 96.94% ± 2.35 of the total oil. The analyzed samples differ significantly in their chemical composition. Dominated by high levels of oxygenated monoterpenes (78% and 41%), the oils are rich in 1.8-cineole, camphor, trans-thujone, cis-chrysanthenol and terpinen-4-ol. Firstly, the antibacterial potential of C. cinerea essential oils showed good inhibition against E. coli ATCC25922 and Staphylococcus aureus ATCC25923 with an inhibitory diameter ranging from (16.70–14.64 mm). In addition, the results of the antioxidant effect of these oils showed that they have moderately weaker antioxidant power than ascorbic acid. On the other hand, these EOs showed significant antifungal potential against the two fungi tested.

How Have Saharan Breeder Been Able to Secure Food for Their Herds During the Containment of COVID-19? Case of Oued Souf, Algeria

Background: In Algeria, COVID-19 containment procedures 2020-2021 have put the livestock sector in a critical situation, particularly in the Saharan regions where animal feed is based on supplies from other regions. Indeed, a famine has threatened the herds, but the breeders have been able to save their animals by an unconventional diet. The knowledge of these nutritional measures and know-how makes it possibleto evaluate local products andto guide Algerian decision-makers towards a safer food strategy that is well adapted to the Sahara region. Methods: We used the “12MO method”, which is a retrospective survey based on the declarations of the breeders for the last twelve months. 12MO served as a basic tool for a systemic analysis conducted in 110 farms in different areas of Oued Souf (Sahara of Algeria). Result: The results highlighted changes in animal feed, under the impact of COVID-19 pandemic through unconventional feeding. 6 feeds were distinguished, including 4 crop residues (PoCR; PeCR; CCR ; TCR) and 2 by-products (PD By-P; PD By-P). During a year of containment, it was not only the interrelationship (agriculture/livestock) that has secured the feeding herds in the Saharan environment, but the breeder’s solidarity has significantly contributed in that also.

Phytochemical and Antibacterial Evaluations of a Medicinal Plant, Carthamus tinctorius L Cultivated in the South West of the Sahara of Algeria in the Wilaya of Adrar

This work was carried out on Carthamus tinctorius, on which we performed the extraction of secondary metabolites using cold maceration using a solvent consisting of methanol and acetone and water (7/7/6: V/V/V). We were able to determine the density of polyphenols, flavonoids and condensed tannins present in this medicinal plant. We also studied its antibacterial power tested on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, by a method called “disc diffusion method”. The contents found are 0.25 mg CE/g DM in condensed tannins, 1.17 mg CE/g DM in flavonoids, and 7.18 mg GAE/g DM in polyphenols. The E. coli bacterium is the only one that was sensitive and whose zone of inhibition has a diameter equal to 14 mm. The minimum inhibitory concentration (MIC) of E. coli is equal to 100 mg/mL, and the minimum bactericidal concentration (MBC) is equal to 150 mg/mL; therefore the MBC/MIC ratio of the hydromethanolic extract of C. tinctorius is approximately 1.5, this enabled us to demonstrate that this extract has a bactericidal effect.

Performance of a PV field's discontinuous two-position sun tracker systems supplying a water pumping system: Concept, theoretical and experimental studies – A case study of the Adrar area in Algeria's Sahara

A discontinuous East-West two-position tracking system (DT-2P), in which the control only sends two orders a day, is a good solution for balancing the benefits and drawbacks of continuous tracking and fixed systems. A theoretical study applied of Adrar, an area in Algeria's south, will be conducted initially, regarding the different parameters of the DT-2P, i.e. azimuth angle for one-axis DT-2P is called 1ADT-2P, when the DT-2P tilted angle equal to latitude, and both azimuth and tilt angles for two-axis DT-2P, called 2ADT-2P, when the DT-2P tilted at the monthly optimum angles. Secondly, a pumping system experimental bench with 1ADT-2P PV and fixed PV was done to verify its performance in terms of changing weather. As for 1ADT-2P test outdoor, the increase in the solar radiation with respect to fixed PV is between 28% and 41.5% for five particular days in summer. The PV energy output and water discharge are increased by 40% and 35%, respectively. The similar gains are between 11.48% and 19%, 10% and 13%, respectively, for four particular days in winter. Also, the use of this solar tracking system does not produce much more overheating of the PV panel than the optimally tilted fixed system. Annual irradiation increases for the 1ADT-2P and 2ADT-2P are predicted to be 19% and 37%, respectively. The result shows that, despite its simplicity, the DT-2P concept approximates the continuous tracker's behavior.

Molecular characterization of Echinococcus granulosus sensu lato genotypes in dromedary camels from extreme Sahara of Algeria based on analysis of nad2 and nad5 genetic markers

Cystic echinococcosis is parasitic disease caused by the metacestodes belonging to the Echinococcus granulosus sensu lato (s.l.) species complex. Cystic echinococcosis is of considerable economic and public health importance. It is endemic in both livestock and humans in North African countries, including Algeria. The present study aimed to characterize E. granulosus s.l. genotypes in dromedary camels (Camelus dromedarius) from the extreme Sahara of Algeria, using recently developed mitochondrial genetic markers (NADH dehydrogenase subunit 2 and NADH dehydrogenase subunit 5) for reliable identification of different genotypes. A total of 75 Echinococcus cysts were collected from 49 dromedary camels, including 65 and 10 cysts from 45 and four camels originating from two slaughterhouses of Tindouf and Illizi provinces, respectively. E. granulosus sensu stricto (s.s.) G1 and G3 were identified in camels from both areas based on nad5 (649 bp) gene sequences, whereas E. granulosus s.l. G6 was identified in camels from Tindouf region based on concatenated nad5 and nad2 gene sequences (total 1336 bp). Identified samples clustered into 11 different haplotypes (ALG1-ALG11), including four haplotypes (ALG8-ALG11) for E. granulosus s.s. G1, one haplotype (ALG7) for E. granulosus s.s. G3, and six haplotypes (ALG1-ALG6) for E. granulosus s.l. G6. The present study provides valuable molecular data, including genotyping and haplotypic variability, on E. granulosus s.l. in dromedary camels from two regions in the extreme Sahara of Algeria. Future characterization of the G1, G3, and G6 samples based on sequencing of complete mitochondrial genomes would be of considerable significance for a more comprehensive understanding of molecular epidemiology of CE in Algeria.

Salinity and type of salt effects on seed germination characteristics of medicinal plant Zygophyllum album L. (Zygophyllaceae) native to the Algerian Sahara

Zygophyllum album L. known as "Agga" in vernacular Algerian dialect is one of great traditional remedies used by the native populations, as a treatment for skin diseases, indigestions and diabetes. This medicinal specie is drought resistant and salt tolerant, it plays an important role against desertification, reforestation of degraded lands and soil rehabilitation. Therefore, knowledge of environmental requirements for its seed germination is necessary for plant establishment in field conditions to colonize new territories. The main objective of this paper is to evaluate the influence of salinity level and the type of salts on seed germination characteristics (germination percentage and salinity tolerance index) of this shrub found in the Sahara of Algeria. The test was conducted in a phytotron at a temperature of 25 °C and in the dark for 10 days. The seeds germinated in Petri dishes soaked with aqueous solutions of (NaCl, CaCl2 or Na2SO4) at the same concentrations of 0, 100, 150, 200, 250, 300, 350 and 400 mM. Statistical analysis revealed that germination characteristics were significantly affected by salinity level and salt compositions. Seeds of Z. album were non dormant, exhibited highest germination percentage (100 %) under distilled water and were moderately salt tolerant. Both germination percentage and germination velocity gradually decreased with increasing salinity, irrespective of applied salt types. The salts that induced the inhibition of germination were salt specific and decreasing in following sequence: Na2SO4 > CaCl2 > NaCl. Our results support the statements that different salts exhibit both osmotic stress and ionic toxicity on seed germination.

Metabolic Profile, Biotransformation, Docking Studies and Molecular Dynamics Simulations of Bioactive Compounds Secreted by CG3 Strain.

Actinobacteria isolated from untapped environments and exposed to extreme conditions such as saltpans are a promising source of novel bioactive compounds. These microorganisms can provide new molecules through either the biosynthetic pathway or the biotransformation of organic molecules. In the present study, we performed a chemical metabolic screening of secondary metabolites secreted by the new strain CG3, which was isolated from a saltpan located in the Sahara of Algeria, via high-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC-ESI-HRMS). The results indicated that this strain produced five new polyene macrolactams, kenalactams A–E, along with two known compounds, mitomycin C and 6″-hydroxy-4,2′,3′,4″ tetramethoxy-p-terphenyl. Furthermore, the CG3 isolate could have excellent properties for converting the aglycone isoflavone glycitein to the compounds 6,7-dimethoxy-3-(4-methoxyphenyl)chromen-4-one (50) and 6,7-dimethoxy-3-phenylchromen-4-one (54), and the isoflavone genistein can be converted to 5,7-dimethoxy-3-(4-methoxyphenyl)chromen-4-one (52). Docking studies and molecular dynamics simulations indicated that these three isoflavones, generated via biotransformation, are potent inhibitors of the target protein aromatase (CYP19A1); consequently, they can be used to prevent breast cancer risk in postmenopausal women.

Assessment of Spatial Distribution and Temporal Variations of the Phreatic Groundwater Level Using Geostatistical Modelling: The Case of Oued Souf Valley—Southern East of Algeria

Since the beginning of the 1980s, several regions in the northern Sahara of Algeria have been confronting the rising groundwater. Among all these regions, Oued Souf Valley represented one of the most acute affected by this phenomenon. Due to the natural topography and the insufficient/weakness of water management and miscoordination between different sectors that are represented by intensive exploitation of deep groundwater reservoirs which returns to the shallow aquifer, absence of sewage and drainage network, leakage from drinking water supply system, the groundwater has raised to the surface or near to the surface, affecting the traditional cultural environment and urban areas and degrading all socio-economic aspects of the Oued Souf habitants. To preserve the Oued Souf environment, a vertical drainage system has been constructed. Consequently, in this research, an evaluation of the vertical drainage system performance and its impact on groundwater level stabilization has been performed by mapping the water table of the phreatic groundwater level using geostatistical modeling using ordinary kriging (OK) interpolation method, which has been applied to analyze the spatial and temporal structure of groundwater level fluctuation. Meanwhile, hierarchical cluster analysis (HCA) was applied for grouping the wells based on the groundwater fluctuations for 2008, 2009, 2014, 2016, 2018, and 2021. However, the vertical drainage system reflected a significant decline of groundwater from 2009 to 2018 due to the important drained volumes through it but another rising phenomenon might be threatening the region in the near future and this is what was indicated in the 2021 groundwater level data. Cluster analysis has generated four groups based on their fluctuation means that are increasing from the first group to the fourth group ascendingly. The first cluster grouped the drains that have a shallow depth (average mean of 5.91 mbgl) and declined over the clusters. The clusters are spatially combined with significant separation of the fourth cluster which represents the deepest group (12.89 mbgl). Based on this research, several factors are influencing the stability of the phreatic groundwater level and even the performance of the drainage system, the most important of which is the overexploitation from deep groundwater reservoirs such as complex terminal and continental intercalary (in drinking and irrigation) and even the illegal use of the phreatic groundwater with important quantities for irrigation and illegal industries.

Energy, environmental, economic, and color analysis of geo-exchange energy assisted-insulated north wall solar dryer for onion slices under relatively cloudy and rainy conditions

Preservation of onion surplus during rainy and cloudy days is a big challenge for farmers in the so-far area in northern Sahara of Algeria. Thus, available renewable energies such as geo-exchange and solar energy could be an effective solution. In the current study, an insulated north wall solar dryer (INWSD) integrated with geo-exchange heat exchanger (GHE) with inlet temperature of 80 °C was tested for drying onion slices under cloudy and rainy weather. Solar radiation and ambient temperature were in the range of 0–447 W m−2 and 9.65–26.53 °C, respectively. Drying process took 28 consecutive hours. Average diffusivity was found to be 2.81 × 10−10 m2 s−1 by considering the variation of relative humidity and temperature inside the drying chamber. Specific energy consumption varied between 0.66 and 1.75 kWh/kg with an average of 1.71 kWh/kg. Thermal efficiency was in the range of 1.48%–48.90%, with an average value of 9.52%. The low CO2 emissions of 46.69 kg/year and average payback period of 0.74 year were obtained using the INWSD. Dried onion was with low total color change at 3.79 compared to fresh samples. Therefore, INWSD is a promising technique by comprehensively considering the 3E (energy, economic, economic-environmental) and color analysis.

Effect of camel’s digestive tract treatment on breaking seed germination of Helianthemum lippii (L) Pers. from the Northern Sahara in Algeria

Effect of camel’s digestive tract treatment on breaking seed germination of <i>Helianthemum lippii</i> (L) Pers. from the Northern Sahara in Algeria