The scope of this study is to analyze some aspects of the Algerian earthquake catalogue between 1980 and 2009.Seismicity analysis is based on reliable compilation of earthquake catalogs obtained from different agencie...The scope of this study is to analyze some aspects of the Algerian earthquake catalogue between 1980 and 2009.Seismicity analysis is based on reliable compilation of earthquake catalogs obtained from different agencies.All intensities and magnitudes were converted to Ms magnitude using appropriate relationships.Dependent events were removed using adapted time and space windows.In addition,the completeness of the catalogue as a function of magnitude was determined from the standard deviation of occurrence rate plots,using the Stepp’s methodology.The remaining 2,016 independent earthquakes with Ms 2.2 were used to obtain various parameters(b-value,z-value)to characterize the temporal and spatial seismic activity for the entire northern part of Algeria.Finally,the obtained results are discussed to explain parameters variability.展开更多
One of the most common types of soil degradation is water erosion.It reduces soil quality at the erosion site and may cause sedimentation issues at the deposition site.This phenomenon is estimated using a variety of m...One of the most common types of soil degradation is water erosion.It reduces soil quality at the erosion site and may cause sedimentation issues at the deposition site.This phenomenon is estimated using a variety of models.The Revised Universal Soil Loss Equation(RUSLE)model is the most often used,due to its consistence and low data requirement.It is useful for estimating annual soil loss at the watershed scale.To investigate the relationship between soil erosion and sediment deposition,the combined RUSLE and Sediment Delivery Ratio(SDR)models are used.The Wadi El Hachem watershed is a coastal and mountainous Mediterranean basin with rugged topography and high degree of climatic aggressiveness.Both of these characteristics can have an immediate effect on soil erosion and sediment yield.This research includes estimating the Average Annual Soil Loss(A)and Sediment Yield(SY)in the Wadi El Hachem watershed,mapping different RUSLE factors as well as A and SY,and studying the influence of rainfall erosivity(R)on A and SY in dry and rainy years.The A results vary from 0 to 410 t·ha^(-1)·yr^(-1)with an annual average of 52 t·ha^(-1)·yr^(-1).The Renfro's SDR model was selected as the best model for estimating SY,with standard error,standard deviation,coefficient of variation,and Nash–Sutcliffe efficiency(NSE)values of 0.38%,0.02,0.07%,and 1.00,respectively.The average SY throughout the whole watershed is around 27 t·ha^(-1)·yr^(-1).The SY map for the entire Wadi El Hachem watershed revealed that sediment production zones are mainly concentrated in the Northeast of the basin,at the basin’s outlet,and in the tributaries of the dam.The simulation results of soil loss and sediment yield in dry and rainy years revealed that R is one of the main factors affecting soil erosion and sediment deposition in the Wadi El Hachem watershed.The mean difference in R factor between dry year and rainy year is 671 MJ·mm·ha^(-1)·h^(-1)·yr^(-1).As a result of this fluctuation,the soil loss and sediment yield have increased by 15 and 8 t·ha^(-1)·yr^(-1),respectively.The results of this research can be used to provide scientific and technical support for conservation and management strategies of the Wadi El Hachem watershed.展开更多
AIM:To investigate the prevalence of,and risk factors for,diabetes mellitus(DM) in Algerian patients with chronic hepatitis C virus(HCV) infection and in a control group.METHODS:A cross-sectional study was undertaken....AIM:To investigate the prevalence of,and risk factors for,diabetes mellitus(DM) in Algerian patients with chronic hepatitis C virus(HCV) infection and in a control group.METHODS:A cross-sectional study was undertaken.A total of 416 consecutive patients with viral chronic hepatitis attending the Internal Medicine Department of the University Hospital Center Touhami Benflis in Batna [290 HCV-infected and 126 hepatitis B virus(HBV)-infected patients] were prospectively recruited.RESULTS:The prevalence of DM was higher in HCV-infected patients in comparison with HBV-infected patients(39.1% vs 5%,P < 0.0001).Among patients without cirrhosis,diabetes was more prevalent in HCV-infected patients than in HBV-infected patients(33.5% vs 4.3%,P < 0.0001).Among patients with cirrhosis,diabetes was more prevalent in HCV-infected patients,but the difference was not significant(67.4% vs 20%,P = 0.058).The logistic regression analysis showed that HCV infection [odds ratio(OR) 4.73,95% CI:1.7-13.2],metabolic syndrome(OR 12.35,95% CI:6.18-24.67),family history of diabetes(OR 3.2,95% CI:1.67-6.13) and increased hepatic enzymes(OR 2.22,95% CI:1.1-4.5) were independently related to DM in these patients.CONCLUSION:The high prevalence of diabetes in HCV-infected patients,and its occurrence at early stages of hepatic disease,suggest that screening for glucose abnormalities should be indicated in these patients.展开更多
Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, loca...Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, located in the northeastern Algeria, to determine the environmental factors controlling the composition and distribution of plant communities. We established a total of 20 transects to measure the vegetation parameters (density and cover) and soil characteristics (electrical conductivity, moisture, pH, CaSO4, CaCO3, organic matter, Na+, K+, Mg2+, Ca2+, SO42 , CI-, NO3- and HCO3-). A total of 17 plant species belonging to seven families were identified. The natural vegetation was composed of halophytic and hydro-halophytic plant communities, presented specially by the species of Amaranthaceae family. Soils in the studied wetlands were moist, gypsiferous, alkaline, salty to very salty with dominance of chloride and calcium. Results of the Canonical Correspondence Analysis (CCA) showed that community structure and species distribution patterns of vegetation were mainly dependent on soil characteristics, mainly being soil salinity (CaSO4, K+, Ca2+ and CI-) and moisture. The distribution of plant species was found to follow a specific zonal pattern. Halocnemum strobilaceum was observed to grow in highly salt-affected soils, thus being the more salt-tolerant species. Phragmites communis plants were widely distributed in the study area with a high density at the edges of accumulated water body. Juncus maritimus, Tamarix gallica and Saficornia fructicosa grew in soils that are partially or completely flooded in winter. Suaeda fructicosa, Traganum nudatum, Arthrocnemum glaucum, Aeluropus littoralis, Cressa cretica and Cynodon dactylon were distributed in salty and moist soils away from the open water body. Plants of Zygophyllum album, Limonastrirum guyonianum, Cornulaca monacantha, Cistanche tinctoria, Mollugo nudicaulis and Sonchus maritimus were found in soils with less salty and moisture. They constituted the outermost belt of vegetation in the studied wetlands. This study will provide a reference on introducing the salt-tolerant plant species as a fodder resource in saline habitats and regenerating the degraded saline wetlands.展开更多
AIM: To analyse allelic frequency of NOD2 gene variantsand to assess their correlation with inflammatory bowel disease(IBD) in Algeria.METHODS: We studied 132 unrelated patients diagnosed with IBD, 86 with Crohn's...AIM: To analyse allelic frequency of NOD2 gene variantsand to assess their correlation with inflammatory bowel disease(IBD) in Algeria.METHODS: We studied 132 unrelated patients diagnosed with IBD, 86 with Crohn's disease(CD) and 46 with ulcerative colitis(UC). Data was prospectively collected between January 2011 and December 2013. The demographic and clinical characteristics were recorded for all the patients. A group of 114 healthy unrelated individuals were selected as controls. All groups studied originated from different regions of North Algeria and confirmed the Algerian origin of their parents and grandparents. Informed and written consent was obtained from each of the participants. All individuals were genotyped for the three CDassociated NOD2 variants(p.Arg702 Trp, p.Gly908 Arg and p.Leu1007 fsins C mutations) using the polymerase chain reaction-restriction fragment length polymorphism method. Allele and genotype frequencies in patients and control subjects were compared by χ2 test and Fisher's exact test where appropriate. Odds ratios(OR) and 95% confidence intervals(95%CI) were also estimated. Association analyses were performed to study the influence of these variants on IBD and on clinical phenotypes.RESULTS: The p.Arg702 Trp mutation showed the highest frequency in CD patients(8%) compared to UC patients(2%)(P = 0.09, OR = 3.67, 95%CI: 0.48-4.87) and controls(5%)(P = 0.4, OR = 1.47, 95%CI: 0.65-3.31). In CD patients allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 3% vs 2%(P = 0.5, OR = 1.67, 95%CI: 0.44-6.34); 2% vs 1%(P = 0.4 OR = 2.69 95%CI: 0.48-14.87 respectively). In UC patients, allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 1% vs 2%(P = 1, OR = 1.62, 95%CI: 0.17-4.74) and 2% vs 1%(P = 0.32, OR = 0.39, 95%CI: 0.05-2.87). The total frequency of the mutated NOD2 chromosomes was higher in CD(13%), than in HC(8%) and UC(5%). In addition, NOD2 variants were linked to a particular clinical sub-phenotype in CD in this Algerian cohort. As expected, the three NOD2 variants showed a significant association with CD but did not reach statistical significance, despite the fact that the allele frequency of NOD2 variants was in the range found in most of the European populations. This might be due to the non-exposure of the NOD2 carriers to environmental factors, required for the expression of the disease.CONCLUSION: Further analyses are necessary to study genetic and environmental factors in IBD in the Algerian population, using larger patient groups.展开更多
A study of thirteen geothermal springs located in the geothermal field of Guelma,northeastern Algeria,was conducted.Samples were collected during the period between January 2014 and February 2016.Geochemical processes...A study of thirteen geothermal springs located in the geothermal field of Guelma,northeastern Algeria,was conducted.Samples were collected during the period between January 2014 and February 2016.Geochemical processes responsible for the chemical composition of thermal and mineralized water were evaluated.The hydrochemical analysis shows that the thermal waters are characterized by the presence of two different chemical facies,the first type SO4-Ca in the east,west and south of Guelma,the second type HCO3-Ca in the south.This analysis also attributed to sodium,chlorides,and sulfates to an evaporitic terrigenous origin by the molar ratio Sr2+/Ca2+.The thermal spring waters from Guelma geothermal system have a meteoric origin,and all samples are immature with strong mixing between hot and shallow waters with 19-38.5%rate of mixing.The silica geothermometer shows that these thermal waters have a temperature varying from 84 to 122℃and that the water came from a depth of 2100-3000 m through a fault system that limits the pullapart basin of Guelma.Potential environmental effluent from thermal spas could pollute in both the irrigation and drinking waters,and which imposes danger on the health of the inhabitants of the region.展开更多
This phyto-ecological study is on halophilic and salt-resistant vegetation of Oran region. The semiarid and sometimes arid climate has been defined and confirmed from a bioclimatic point of view. The pedological appro...This phyto-ecological study is on halophilic and salt-resistant vegetation of Oran region. The semiarid and sometimes arid climate has been defined and confirmed from a bioclimatic point of view. The pedological approach used shows a soil with sandy to silty-sandy texture, favoring regression of the vegetation and a halophilic vegetation set up. In this study, we analyze the floristic composition of the northern region of Hammam Boughrara using multiple floristic surveys conducted at three stations along the Tafna wadi. Dominated by Mediterranean and Saharo-Sindian elements, the relatively poor flora (88 species in total) is biologically characterized by a clear dominance of therophytes (>33%) and chamaephytes (>19%) to the detriment of phanerophytes.展开更多
The concept of load-carrying capacity of the soil can be evaluated by two main components: permissible stress and permissible depth;and therefore, running it begins its assessment that allows an outline of exploitatio...The concept of load-carrying capacity of the soil can be evaluated by two main components: permissible stress and permissible depth;and therefore, running it begins its assessment that allows an outline of exploitation. Nevertheless, the assessment of the load-carrying capacity made the object of several works of research and many models, based on the multi-criteria analysis, have been established. This work examines the contribution of GIS approach to assessment load-carrying capacity of the soil. This one has been finished in two practicums: 1) Assessment of the capacity of soil by a multi-criteria approach, using the Weighted Sum Model (WSM);2) It brought to use the GIS approach to evaluate and spatialize degree of soil bearing stresses resulting from the buildings, as well as load distribution. The method has been applied to the Berhoum area of Hodna Basin, in eastern Algeria, where each is characterized by its various natural properties and density of equipment. Final results are better in the classification of the degree of load-carrying capacity possible in each site. This results in allowing exploiters to program their optimal designs for the rational management of the area.展开更多
Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists...Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists. When </span><span style="font-family:Verdana;">these waters are of deep origin, they may have high mineralization and</span><span style="font-family:Verdana;"> chemical compositions unsuitable for irrigation;in particular, they may alter soils and crops. It is therefore important to optimize the spatial estimation of the salinity of these waters and contribute to better knowledge of their quality, through an adapted and robust statistical and geostatistical approach. In the case of north-eastern Algeria, the objective of this study is to characterize the quality of deep waters and to test two interpolation methods (Inverse distance weight and ordinary Kriging) of their electrical conductivity (EC) as an indicator of their salinity and of the risk of damaging irrigated soils. 51 ground</span><span style="font-family:Verdana;">water samples were taken in this region where there are many thermal </span><span style="font-family:Verdana;">springs, the water of which is used for irrigation and often is highly mineralized (EC between 0.6 and 26.6 dS/m). The geology is composed of karstic rocks crossed by large faults that allow deep water to rise. Based on major elements contents, analysis of the hydrochemical facies of these waters shows that the main facies are hyperchlorinated sodium (38%) and sulfated calcium (32%). The RSC (Residual Sodium Carbonate) and SAR (Irrigation water salt) indexes were used to assess the water quality. The results indicate that the majority of the sampled</span><span style="color:red;"> </span><span style="font-family:Verdana;">groundwater present a risk for soils irrigated with these waters (almost 1/3 presents a strong risk). The risk for the soils seems to be explained by the positive value of the residual alkalinity, and the high risks of sodization and alkalinization. The geostatistical analysis reveals strong heterogeneity in electrical conductivity (salinity). The maps based on this analysis allow the identification of risk areas. The comparison of Inverse distance weight and ordinary Kriging methods indicates similar results being obtained through both methods. However, ordinary kriging appears to be more accur</span><span style="font-family:Verdana;">ate, less biased, and seemingly better represents the organization of the </span><span style="font-family:Verdana;">groundw</span><span style="font-family:Verdana;">ater resources, as NE-SW alignments are visible. With the proposed ap</span><span style="font-family:Verdana;">proach, it is possible to calculate the surface areas of the different salinity </span><span style="font-family:Verdana;">thresholds and then optimize the use of deep groundwater for irrigation.展开更多
Background:To study,estimate and discuss the variations of the aerosol optical depth(AOD),black carbon,sulfate and organic matter,in the atmosphere in Blida City of Algeria,which was greatly affected by COVID-19 pande...Background:To study,estimate and discuss the variations of the aerosol optical depth(AOD),black carbon,sulfate and organic matter,in the atmosphere in Blida City of Algeria,which was greatly affected by COVID-19 pandemic.Methods:We analyzed the effects of changes in the total AOD,black carbon,sulfate,and organic matter in the atmosphere(λ=550 nm)in the same period of 2019 and 2020,following the COVID-19 epidemic in Blida City,which was the most-affected city in Algeria.Results:The quarantine that was enacted to limit the spread of COVID-19 resulted in side effects that were identifiable in the total AOD and in some of its atmospheric components.Comparing these variables in 2019 and 2020(in the months during the quarantine)revealed that in April,the BCAOD values were much lower in 2020than in 2019.Conclusion:Based on the effects of the emerging COVID-19,the research listed the changes received from the AOD,and is considered as a comparative study and represents a significant side effect of the quarantine that was mainly designed to limit COVID-19.展开更多
The Edough massif is the easternmost crystalline massif of the Maghrebides which represent the southeastern part of the West Mediterranean orogen.It occurs below the greenschist-facies Tellian units that represent the...The Edough massif is the easternmost crystalline massif of the Maghrebides which represent the southeastern part of the West Mediterranean orogen.It occurs below the greenschist-facies Tellian units that represent the thrusted Mesozoic to Eocene passive paleomargin of northern Africa deposited on thinned continental crust.The upper unit of the Edough massif is characterized by metasedimentary rocks affected展开更多
AIM: To determine the frequency of various hepatitis C virus (HCV) genotypes present in patients from north eastern Algeria. METHODS: This is a retrospective cross-sectional study of 435 HCV infected patients from nor...AIM: To determine the frequency of various hepatitis C virus (HCV) genotypes present in patients from north eastern Algeria. METHODS: This is a retrospective cross-sectional study of 435 HCV infected patients from northeast Algeria, detected in the Sadelaoud laboratory and diagnosed between January 2010 and December 2012. The patients were diagnosed with HCV infection in their local hospitals and referred to be assessed for HCV genotype before the antiviral treatment. Demographic information (sex, age and address), genotype, subtype and viral load were retrieved from the patient medical records. The serum samples were tested by the type-specific genotyping assay.RESULTS: The majority of the patients (82.5%) were from the central part of the examined region (P = 0.002). The mean age of the patients studied was 53.6 ± 11.5 years. HCV genotype 1 was the most frequent (88.7%), followed by genotypes 2 (8.5%), 4 (1.1%), 3 (0.9%) and 5 (0.2%). Genotype 6 was not detected in these patients. Mixed infection across the HCV subtypes was detected in twenty patients (4.6%). The genotype distribution was related to age and region. Genotype 1 was significantly less frequent in the ≥ 60 age group than in the younger age group (OR = 0.2; 95%CI: 0.1-0.5, P < 0.001). Furthermore, genotype 1 was more frequent in the central part of the examined region than elsewhere (P < 0.01). CONCLUSION: The HCV genotype (type 1b was dominant) distribution in Algeria is different from those in other northern countries of Africa.展开更多
The degradation of the natural resources in Algeria nowadays remains a major constraint for the agrosilvopastoral development. Indeed, the area of Beni Saf is confronted with many problems such as the anthropozoic pre...The degradation of the natural resources in Algeria nowadays remains a major constraint for the agrosilvopastoral development. Indeed, the area of Beni Saf is confronted with many problems such as the anthropozoic pressure which does not make it possible to keep balance between the exploitation of the natural resources and their regenerations in time and space. Following the example results obtained through a floristic study by the factorial analysis of correspondences (F A C), concerning the identification of anthropozoogenes species such as: Chamaerops humilis, Asphodelus microcarpus, Withania frutescens, Calycotome spinosa, Asparagus albus;furthermore, the calculation of the disturbance index which marks the rate of therophytisation which is about 68%, that one finds it very high. These indices show a disturbance and an imbalance of the plant formation of the zone of study, caused by the high anthropozoogene pressure. Vis-a-vis this threat, it is essential to propose a possibility of intervention for a durable management of these spaces.展开更多
Due to the accelerated population growth and development in all sectors especially industry, more water has been pumped and more effluents have been rejected to the natural system. In the coastal Skikda Valley;Petroch...Due to the accelerated population growth and development in all sectors especially industry, more water has been pumped and more effluents have been rejected to the natural system. In the coastal Skikda Valley;Petrochemical industry is practiced along the year and almost groundwater are threatened. This work is referred to the characterization of the environmental hydrobiochemistry in the coastal petrochemical industrial area. The study has investigated the groundwater pollution by hydrocarbons using biochemical approach and assessing the nature and extent of contamination of groundwater in relation to petroleum industrial activities surrounding tank, channel and pipe. At site of this industrial zone, groundwater circulates on slight deep in the mio-pliocene alluviums (sand and gravel) which is characterized by an important permeability. Groundwater quality analysis proved that groundwater quality is largely polluted with respect to BOD5, COD, TPH and TSS. So, a narrow relationship between BOD and TPH and important qualitative degradation of the groundwater is shown, especially in the parts situated in the down gradient area and in direct proximity of tank, channel and pipe. The extent of groundwater contamination is influencing by the depth of the water table, permeability of the soil and therefore infiltration rate. In order to prevent further pollution of groundwater, oil must be stored and transported via impervious tank, pipe and channel. So, effluents must be treated prior to discharge.展开更多
In North Africa, Cedrus atlantica forests are in decline, following decades of anthropogenic pressure and repeated drought events. Mixed C. atlantica-Quercus ilex stands located in the Theniet El Had National Park (no...In North Africa, Cedrus atlantica forests are in decline, following decades of anthropogenic pressure and repeated drought events. Mixed C. atlantica-Quercus ilex stands located in the Theniet El Had National Park (northwestern Algeria) were considered in the present study. Based on a stratified sampling, six temporary plots were established to describe structure (species composition, density, total height, diameter and basal area) and radial growth in relation to type of stand (pure and mixed), using a dendroecological approach. The diameter distribution of C. atlantica indicated the presence of few young individuals and a poor regeneration status in all the stands. The density and basal area of C. atlantica were significantly higher in pure stands, which necessitate silvicultural operations. In contrast, Q. ilex showed a progressive dynamic, at moderate altitude. Radial growth showed a significant decline from 1980 to the 2000s. The absence of an appropriate management plan and the increase in anthropogenic effects, without ruling out a role for the current climate conditions marked by drought, seem to be the causes of C. atlantica decline.展开更多
Mediterranean large lakes play an important role in providing a range of ecosystem functions and supporting biodiversity. The conservation and management of these lakes require more detailed knowledge of their ecology...Mediterranean large lakes play an important role in providing a range of ecosystem functions and supporting biodiversity. The conservation and management of these lakes require more detailed knowledge of their ecology and environment-vegetation relationships. Chotts are probably the most poorly understood lake ecosystems. Chott Zehrez (Djelfa) as a large, shallow lake ecosystem in Algerian steppes, where wetlands are important part of their productivity. Despite the status of chott Zehrez lake as a Ramsar site, the main threat to its conservation is the private nature of surrounding land holdings in addition to the lack of knowledge and awareness by the local population of the importance of lake ecosystems. A wealth of halophytic flora exists which can be exploited for an array of uses like fodder, fuel wood, oilseed, medicines, landscaping, and environment conservation through carbon sequestration. A total 112 species belonging to 26 families and 39 genera were recorded. The sabkha flora includes 9 endangered and endemic species such as Avena bromoides, Cutandia divaricata, Herniaria mauritanica and Salicornia arabica. In this paper we mainly discussed characteristics and importance of Chott Zehrez lake ecosystem, its vegetation potentialities and economic usages will be also presented and discussed. Finally conservation strategy and restoration of this ecosystem are suggested.展开更多
The objective of this study is to determine the influence of soil physico-chemical factors on the spatial distribution of matorrals in the plain from Remchi to Béni-Saf located in the western region of Algeria. T...The objective of this study is to determine the influence of soil physico-chemical factors on the spatial distribution of matorrals in the plain from Remchi to Béni-Saf located in the western region of Algeria. This study informs us of the relationships that soil can have on the diversity of matorrals. On the bioclimatic level, the region is characterized by semi-aridity accentuating the phenomena of thérophysation. Soil analyzes carried out using known methods (Stokes Particle Size Method, Electrometric Method for pH, 1/5 Extract Method for Electrical Conductivity, Bernard Calcium Method for CaCO3, Anne Method for Organic Carbon). The results show a textural diversity;sandy-muddy “Remchi”, sandy “Rachgoun 1 and Rechgoun 2”, not far from Béni-Saf. The low clay content (Remchi: Profile 1: Horizon 1: Clays 10%, Profile 2: Horizon 1: Clays 16%, Profile 3: Horizon 1: Clays 5%, Rechgoun: Profile 1: Horizon 1: Clays 3%, Profile 3: Horizon 1: 2% Clays and Horizon 2: 3% Clays) leads to poor structural stability leading to degradation of the soil surface through erosion. The latter is revealed by the presence of small erosion claws visible on these rough slopes or almost.展开更多
This aim of this study is to highlight the critical view of human action and anthropic at the steppe zone of Tlemcen. Therefore, the current paper tends to tackle an analytical study of the dynamics of ecosystems in b...This aim of this study is to highlight the critical view of human action and anthropic at the steppe zone of Tlemcen. Therefore, the current paper tends to tackle an analytical study of the dynamics of ecosystems in both states: El-Gor in the south-east and El-Bouihi in the southern-west of Tlemcen. To carry out this study it was necessary to present the bioclimatic context based on weather data to perform bioclimatic syntheses (diagram ombrothermic, climagramme rainfall Emberger). By comparison between old and recent periods (1913-1938) and (1984-2009), respectively, for the region of El-Gor and (1913-1938) and (1970-1990) for the El station-Bouihi, there is a net decrease in rainfall and higher temperatures at the new periods, which means that the study areas are moving towards the driest floors. The interpretation of multidimensional treatments AFC (Factor Analysis of Correspondences) vegetation helps to determine the existing affinities between the different taxa. These biostatistical analyses help to highlight the different factors often responsible for the dynamic regressive most cases.展开更多
Relying essentially on human data (social structure, demography, population repartitions, migratory movements, agro-pastural activities), the authors, from their studies, note that these regions are an extension of ha...Relying essentially on human data (social structure, demography, population repartitions, migratory movements, agro-pastural activities), the authors, from their studies, note that these regions are an extension of hamlets and other groups. Highlands gather a small population that seems to settle. Responsible human disturbance (clearings, cultures, urbanization, etc.) modified a large part of the actual state of vegetation structures. The results also show that most of the population is concentrated in the main towns. This concentration causes consumption of pre-forest land and rangelands. The average annual extension can sometimes reach 2.4 Ha. Hamlets, home grouping seem to impose a lifestyle approaching that of centers located in the North. At the bioclimatic level, the results show that the cold thermal variations promote contact between woody vegetation and steppe formations with thermal determinism (formation often in xerophytes thorny pads). Droughts often advocate regressive dynamics of these plant formations which are quite degraded. On the other hand, stressing continuity issues related to human actions, the authors present the floristic composition, detailing the botanical plant species including biological and morphological types. The therophyte type predominates in all areas explored and their percentage can reach 73% in the steppe and 49% in Beni-Snous.展开更多
文摘The scope of this study is to analyze some aspects of the Algerian earthquake catalogue between 1980 and 2009.Seismicity analysis is based on reliable compilation of earthquake catalogs obtained from different agencies.All intensities and magnitudes were converted to Ms magnitude using appropriate relationships.Dependent events were removed using adapted time and space windows.In addition,the completeness of the catalogue as a function of magnitude was determined from the standard deviation of occurrence rate plots,using the Stepp’s methodology.The remaining 2,016 independent earthquakes with Ms 2.2 were used to obtain various parameters(b-value,z-value)to characterize the temporal and spatial seismic activity for the entire northern part of Algeria.Finally,the obtained results are discussed to explain parameters variability.
基金the framework of the SWATCH project (Prima project)funded by the DGRSDT,Algeria
文摘One of the most common types of soil degradation is water erosion.It reduces soil quality at the erosion site and may cause sedimentation issues at the deposition site.This phenomenon is estimated using a variety of models.The Revised Universal Soil Loss Equation(RUSLE)model is the most often used,due to its consistence and low data requirement.It is useful for estimating annual soil loss at the watershed scale.To investigate the relationship between soil erosion and sediment deposition,the combined RUSLE and Sediment Delivery Ratio(SDR)models are used.The Wadi El Hachem watershed is a coastal and mountainous Mediterranean basin with rugged topography and high degree of climatic aggressiveness.Both of these characteristics can have an immediate effect on soil erosion and sediment yield.This research includes estimating the Average Annual Soil Loss(A)and Sediment Yield(SY)in the Wadi El Hachem watershed,mapping different RUSLE factors as well as A and SY,and studying the influence of rainfall erosivity(R)on A and SY in dry and rainy years.The A results vary from 0 to 410 t·ha^(-1)·yr^(-1)with an annual average of 52 t·ha^(-1)·yr^(-1).The Renfro's SDR model was selected as the best model for estimating SY,with standard error,standard deviation,coefficient of variation,and Nash–Sutcliffe efficiency(NSE)values of 0.38%,0.02,0.07%,and 1.00,respectively.The average SY throughout the whole watershed is around 27 t·ha^(-1)·yr^(-1).The SY map for the entire Wadi El Hachem watershed revealed that sediment production zones are mainly concentrated in the Northeast of the basin,at the basin’s outlet,and in the tributaries of the dam.The simulation results of soil loss and sediment yield in dry and rainy years revealed that R is one of the main factors affecting soil erosion and sediment deposition in the Wadi El Hachem watershed.The mean difference in R factor between dry year and rainy year is 671 MJ·mm·ha^(-1)·h^(-1)·yr^(-1).As a result of this fluctuation,the soil loss and sediment yield have increased by 15 and 8 t·ha^(-1)·yr^(-1),respectively.The results of this research can be used to provide scientific and technical support for conservation and management strategies of the Wadi El Hachem watershed.
文摘AIM:To investigate the prevalence of,and risk factors for,diabetes mellitus(DM) in Algerian patients with chronic hepatitis C virus(HCV) infection and in a control group.METHODS:A cross-sectional study was undertaken.A total of 416 consecutive patients with viral chronic hepatitis attending the Internal Medicine Department of the University Hospital Center Touhami Benflis in Batna [290 HCV-infected and 126 hepatitis B virus(HBV)-infected patients] were prospectively recruited.RESULTS:The prevalence of DM was higher in HCV-infected patients in comparison with HBV-infected patients(39.1% vs 5%,P < 0.0001).Among patients without cirrhosis,diabetes was more prevalent in HCV-infected patients than in HBV-infected patients(33.5% vs 4.3%,P < 0.0001).Among patients with cirrhosis,diabetes was more prevalent in HCV-infected patients,but the difference was not significant(67.4% vs 20%,P = 0.058).The logistic regression analysis showed that HCV infection [odds ratio(OR) 4.73,95% CI:1.7-13.2],metabolic syndrome(OR 12.35,95% CI:6.18-24.67),family history of diabetes(OR 3.2,95% CI:1.67-6.13) and increased hepatic enzymes(OR 2.22,95% CI:1.1-4.5) were independently related to DM in these patients.CONCLUSION:The high prevalence of diabetes in HCV-infected patients,and its occurrence at early stages of hepatic disease,suggest that screening for glucose abnormalities should be indicated in these patients.
基金the Saharan Bio-resources Laboratory,Safeguarding and Valorization,Kasdi Merbah University of Ouargla,Algeria for providing support for this research
文摘Saline wetlands are rare ecosystems in Saharan areas, which are important for conservation of many endemic and rare plant species. In this study, we investigated five saline wetland sites of the Oued Righ region, located in the northeastern Algeria, to determine the environmental factors controlling the composition and distribution of plant communities. We established a total of 20 transects to measure the vegetation parameters (density and cover) and soil characteristics (electrical conductivity, moisture, pH, CaSO4, CaCO3, organic matter, Na+, K+, Mg2+, Ca2+, SO42 , CI-, NO3- and HCO3-). A total of 17 plant species belonging to seven families were identified. The natural vegetation was composed of halophytic and hydro-halophytic plant communities, presented specially by the species of Amaranthaceae family. Soils in the studied wetlands were moist, gypsiferous, alkaline, salty to very salty with dominance of chloride and calcium. Results of the Canonical Correspondence Analysis (CCA) showed that community structure and species distribution patterns of vegetation were mainly dependent on soil characteristics, mainly being soil salinity (CaSO4, K+, Ca2+ and CI-) and moisture. The distribution of plant species was found to follow a specific zonal pattern. Halocnemum strobilaceum was observed to grow in highly salt-affected soils, thus being the more salt-tolerant species. Phragmites communis plants were widely distributed in the study area with a high density at the edges of accumulated water body. Juncus maritimus, Tamarix gallica and Saficornia fructicosa grew in soils that are partially or completely flooded in winter. Suaeda fructicosa, Traganum nudatum, Arthrocnemum glaucum, Aeluropus littoralis, Cressa cretica and Cynodon dactylon were distributed in salty and moist soils away from the open water body. Plants of Zygophyllum album, Limonastrirum guyonianum, Cornulaca monacantha, Cistanche tinctoria, Mollugo nudicaulis and Sonchus maritimus were found in soils with less salty and moisture. They constituted the outermost belt of vegetation in the studied wetlands. This study will provide a reference on introducing the salt-tolerant plant species as a fodder resource in saline habitats and regenerating the degraded saline wetlands.
基金Supported by the Agence Thématique de la Recherche Scientifique en Santé,(ATRSS,ex ANDRS)(PNR N°37-ANDRS-2011)
文摘AIM: To analyse allelic frequency of NOD2 gene variantsand to assess their correlation with inflammatory bowel disease(IBD) in Algeria.METHODS: We studied 132 unrelated patients diagnosed with IBD, 86 with Crohn's disease(CD) and 46 with ulcerative colitis(UC). Data was prospectively collected between January 2011 and December 2013. The demographic and clinical characteristics were recorded for all the patients. A group of 114 healthy unrelated individuals were selected as controls. All groups studied originated from different regions of North Algeria and confirmed the Algerian origin of their parents and grandparents. Informed and written consent was obtained from each of the participants. All individuals were genotyped for the three CDassociated NOD2 variants(p.Arg702 Trp, p.Gly908 Arg and p.Leu1007 fsins C mutations) using the polymerase chain reaction-restriction fragment length polymorphism method. Allele and genotype frequencies in patients and control subjects were compared by χ2 test and Fisher's exact test where appropriate. Odds ratios(OR) and 95% confidence intervals(95%CI) were also estimated. Association analyses were performed to study the influence of these variants on IBD and on clinical phenotypes.RESULTS: The p.Arg702 Trp mutation showed the highest frequency in CD patients(8%) compared to UC patients(2%)(P = 0.09, OR = 3.67, 95%CI: 0.48-4.87) and controls(5%)(P = 0.4, OR = 1.47, 95%CI: 0.65-3.31). In CD patients allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 3% vs 2%(P = 0.5, OR = 1.67, 95%CI: 0.44-6.34); 2% vs 1%(P = 0.4 OR = 2.69 95%CI: 0.48-14.87 respectively). In UC patients, allelic frequencies of p.Gly908 Arg and p.Leu1007 fsins C variants compared to HC were 1% vs 2%(P = 1, OR = 1.62, 95%CI: 0.17-4.74) and 2% vs 1%(P = 0.32, OR = 0.39, 95%CI: 0.05-2.87). The total frequency of the mutated NOD2 chromosomes was higher in CD(13%), than in HC(8%) and UC(5%). In addition, NOD2 variants were linked to a particular clinical sub-phenotype in CD in this Algerian cohort. As expected, the three NOD2 variants showed a significant association with CD but did not reach statistical significance, despite the fact that the allele frequency of NOD2 variants was in the range found in most of the European populations. This might be due to the non-exposure of the NOD2 carriers to environmental factors, required for the expression of the disease.CONCLUSION: Further analyses are necessary to study genetic and environmental factors in IBD in the Algerian population, using larger patient groups.
文摘A study of thirteen geothermal springs located in the geothermal field of Guelma,northeastern Algeria,was conducted.Samples were collected during the period between January 2014 and February 2016.Geochemical processes responsible for the chemical composition of thermal and mineralized water were evaluated.The hydrochemical analysis shows that the thermal waters are characterized by the presence of two different chemical facies,the first type SO4-Ca in the east,west and south of Guelma,the second type HCO3-Ca in the south.This analysis also attributed to sodium,chlorides,and sulfates to an evaporitic terrigenous origin by the molar ratio Sr2+/Ca2+.The thermal spring waters from Guelma geothermal system have a meteoric origin,and all samples are immature with strong mixing between hot and shallow waters with 19-38.5%rate of mixing.The silica geothermometer shows that these thermal waters have a temperature varying from 84 to 122℃and that the water came from a depth of 2100-3000 m through a fault system that limits the pullapart basin of Guelma.Potential environmental effluent from thermal spas could pollute in both the irrigation and drinking waters,and which imposes danger on the health of the inhabitants of the region.
文摘This phyto-ecological study is on halophilic and salt-resistant vegetation of Oran region. The semiarid and sometimes arid climate has been defined and confirmed from a bioclimatic point of view. The pedological approach used shows a soil with sandy to silty-sandy texture, favoring regression of the vegetation and a halophilic vegetation set up. In this study, we analyze the floristic composition of the northern region of Hammam Boughrara using multiple floristic surveys conducted at three stations along the Tafna wadi. Dominated by Mediterranean and Saharo-Sindian elements, the relatively poor flora (88 species in total) is biologically characterized by a clear dominance of therophytes (>33%) and chamaephytes (>19%) to the detriment of phanerophytes.
文摘The concept of load-carrying capacity of the soil can be evaluated by two main components: permissible stress and permissible depth;and therefore, running it begins its assessment that allows an outline of exploitation. Nevertheless, the assessment of the load-carrying capacity made the object of several works of research and many models, based on the multi-criteria analysis, have been established. This work examines the contribution of GIS approach to assessment load-carrying capacity of the soil. This one has been finished in two practicums: 1) Assessment of the capacity of soil by a multi-criteria approach, using the Weighted Sum Model (WSM);2) It brought to use the GIS approach to evaluate and spatialize degree of soil bearing stresses resulting from the buildings, as well as load distribution. The method has been applied to the Berhoum area of Hodna Basin, in eastern Algeria, where each is characterized by its various natural properties and density of equipment. Final results are better in the classification of the degree of load-carrying capacity possible in each site. This results in allowing exploiters to program their optimal designs for the rational management of the area.
文摘Faced with the scarcity of surface water accentuated by climate change, particularly in many arid and semi-arid countries, the quality of groundwater used for irrigation is a concern to agronomists and hydrogeologists. When </span><span style="font-family:Verdana;">these waters are of deep origin, they may have high mineralization and</span><span style="font-family:Verdana;"> chemical compositions unsuitable for irrigation;in particular, they may alter soils and crops. It is therefore important to optimize the spatial estimation of the salinity of these waters and contribute to better knowledge of their quality, through an adapted and robust statistical and geostatistical approach. In the case of north-eastern Algeria, the objective of this study is to characterize the quality of deep waters and to test two interpolation methods (Inverse distance weight and ordinary Kriging) of their electrical conductivity (EC) as an indicator of their salinity and of the risk of damaging irrigated soils. 51 ground</span><span style="font-family:Verdana;">water samples were taken in this region where there are many thermal </span><span style="font-family:Verdana;">springs, the water of which is used for irrigation and often is highly mineralized (EC between 0.6 and 26.6 dS/m). The geology is composed of karstic rocks crossed by large faults that allow deep water to rise. Based on major elements contents, analysis of the hydrochemical facies of these waters shows that the main facies are hyperchlorinated sodium (38%) and sulfated calcium (32%). The RSC (Residual Sodium Carbonate) and SAR (Irrigation water salt) indexes were used to assess the water quality. The results indicate that the majority of the sampled</span><span style="color:red;"> </span><span style="font-family:Verdana;">groundwater present a risk for soils irrigated with these waters (almost 1/3 presents a strong risk). The risk for the soils seems to be explained by the positive value of the residual alkalinity, and the high risks of sodization and alkalinization. The geostatistical analysis reveals strong heterogeneity in electrical conductivity (salinity). The maps based on this analysis allow the identification of risk areas. The comparison of Inverse distance weight and ordinary Kriging methods indicates similar results being obtained through both methods. However, ordinary kriging appears to be more accur</span><span style="font-family:Verdana;">ate, less biased, and seemingly better represents the organization of the </span><span style="font-family:Verdana;">groundw</span><span style="font-family:Verdana;">ater resources, as NE-SW alignments are visible. With the proposed ap</span><span style="font-family:Verdana;">proach, it is possible to calculate the surface areas of the different salinity </span><span style="font-family:Verdana;">thresholds and then optimize the use of deep groundwater for irrigation.
文摘Background:To study,estimate and discuss the variations of the aerosol optical depth(AOD),black carbon,sulfate and organic matter,in the atmosphere in Blida City of Algeria,which was greatly affected by COVID-19 pandemic.Methods:We analyzed the effects of changes in the total AOD,black carbon,sulfate,and organic matter in the atmosphere(λ=550 nm)in the same period of 2019 and 2020,following the COVID-19 epidemic in Blida City,which was the most-affected city in Algeria.Results:The quarantine that was enacted to limit the spread of COVID-19 resulted in side effects that were identifiable in the total AOD and in some of its atmospheric components.Comparing these variables in 2019 and 2020(in the months during the quarantine)revealed that in April,the BCAOD values were much lower in 2020than in 2019.Conclusion:Based on the effects of the emerging COVID-19,the research listed the changes received from the AOD,and is considered as a comparative study and represents a significant side effect of the quarantine that was mainly designed to limit COVID-19.
文摘The Edough massif is the easternmost crystalline massif of the Maghrebides which represent the southeastern part of the West Mediterranean orogen.It occurs below the greenschist-facies Tellian units that represent the thrusted Mesozoic to Eocene passive paleomargin of northern Africa deposited on thinned continental crust.The upper unit of the Edough massif is characterized by metasedimentary rocks affected
文摘AIM: To determine the frequency of various hepatitis C virus (HCV) genotypes present in patients from north eastern Algeria. METHODS: This is a retrospective cross-sectional study of 435 HCV infected patients from northeast Algeria, detected in the Sadelaoud laboratory and diagnosed between January 2010 and December 2012. The patients were diagnosed with HCV infection in their local hospitals and referred to be assessed for HCV genotype before the antiviral treatment. Demographic information (sex, age and address), genotype, subtype and viral load were retrieved from the patient medical records. The serum samples were tested by the type-specific genotyping assay.RESULTS: The majority of the patients (82.5%) were from the central part of the examined region (P = 0.002). The mean age of the patients studied was 53.6 ± 11.5 years. HCV genotype 1 was the most frequent (88.7%), followed by genotypes 2 (8.5%), 4 (1.1%), 3 (0.9%) and 5 (0.2%). Genotype 6 was not detected in these patients. Mixed infection across the HCV subtypes was detected in twenty patients (4.6%). The genotype distribution was related to age and region. Genotype 1 was significantly less frequent in the ≥ 60 age group than in the younger age group (OR = 0.2; 95%CI: 0.1-0.5, P < 0.001). Furthermore, genotype 1 was more frequent in the central part of the examined region than elsewhere (P < 0.01). CONCLUSION: The HCV genotype (type 1b was dominant) distribution in Algeria is different from those in other northern countries of Africa.
文摘The degradation of the natural resources in Algeria nowadays remains a major constraint for the agrosilvopastoral development. Indeed, the area of Beni Saf is confronted with many problems such as the anthropozoic pressure which does not make it possible to keep balance between the exploitation of the natural resources and their regenerations in time and space. Following the example results obtained through a floristic study by the factorial analysis of correspondences (F A C), concerning the identification of anthropozoogenes species such as: Chamaerops humilis, Asphodelus microcarpus, Withania frutescens, Calycotome spinosa, Asparagus albus;furthermore, the calculation of the disturbance index which marks the rate of therophytisation which is about 68%, that one finds it very high. These indices show a disturbance and an imbalance of the plant formation of the zone of study, caused by the high anthropozoogene pressure. Vis-a-vis this threat, it is essential to propose a possibility of intervention for a durable management of these spaces.
文摘Due to the accelerated population growth and development in all sectors especially industry, more water has been pumped and more effluents have been rejected to the natural system. In the coastal Skikda Valley;Petrochemical industry is practiced along the year and almost groundwater are threatened. This work is referred to the characterization of the environmental hydrobiochemistry in the coastal petrochemical industrial area. The study has investigated the groundwater pollution by hydrocarbons using biochemical approach and assessing the nature and extent of contamination of groundwater in relation to petroleum industrial activities surrounding tank, channel and pipe. At site of this industrial zone, groundwater circulates on slight deep in the mio-pliocene alluviums (sand and gravel) which is characterized by an important permeability. Groundwater quality analysis proved that groundwater quality is largely polluted with respect to BOD5, COD, TPH and TSS. So, a narrow relationship between BOD and TPH and important qualitative degradation of the groundwater is shown, especially in the parts situated in the down gradient area and in direct proximity of tank, channel and pipe. The extent of groundwater contamination is influencing by the depth of the water table, permeability of the soil and therefore infiltration rate. In order to prevent further pollution of groundwater, oil must be stored and transported via impervious tank, pipe and channel. So, effluents must be treated prior to discharge.
文摘In North Africa, Cedrus atlantica forests are in decline, following decades of anthropogenic pressure and repeated drought events. Mixed C. atlantica-Quercus ilex stands located in the Theniet El Had National Park (northwestern Algeria) were considered in the present study. Based on a stratified sampling, six temporary plots were established to describe structure (species composition, density, total height, diameter and basal area) and radial growth in relation to type of stand (pure and mixed), using a dendroecological approach. The diameter distribution of C. atlantica indicated the presence of few young individuals and a poor regeneration status in all the stands. The density and basal area of C. atlantica were significantly higher in pure stands, which necessitate silvicultural operations. In contrast, Q. ilex showed a progressive dynamic, at moderate altitude. Radial growth showed a significant decline from 1980 to the 2000s. The absence of an appropriate management plan and the increase in anthropogenic effects, without ruling out a role for the current climate conditions marked by drought, seem to be the causes of C. atlantica decline.
文摘Mediterranean large lakes play an important role in providing a range of ecosystem functions and supporting biodiversity. The conservation and management of these lakes require more detailed knowledge of their ecology and environment-vegetation relationships. Chotts are probably the most poorly understood lake ecosystems. Chott Zehrez (Djelfa) as a large, shallow lake ecosystem in Algerian steppes, where wetlands are important part of their productivity. Despite the status of chott Zehrez lake as a Ramsar site, the main threat to its conservation is the private nature of surrounding land holdings in addition to the lack of knowledge and awareness by the local population of the importance of lake ecosystems. A wealth of halophytic flora exists which can be exploited for an array of uses like fodder, fuel wood, oilseed, medicines, landscaping, and environment conservation through carbon sequestration. A total 112 species belonging to 26 families and 39 genera were recorded. The sabkha flora includes 9 endangered and endemic species such as Avena bromoides, Cutandia divaricata, Herniaria mauritanica and Salicornia arabica. In this paper we mainly discussed characteristics and importance of Chott Zehrez lake ecosystem, its vegetation potentialities and economic usages will be also presented and discussed. Finally conservation strategy and restoration of this ecosystem are suggested.
文摘The objective of this study is to determine the influence of soil physico-chemical factors on the spatial distribution of matorrals in the plain from Remchi to Béni-Saf located in the western region of Algeria. This study informs us of the relationships that soil can have on the diversity of matorrals. On the bioclimatic level, the region is characterized by semi-aridity accentuating the phenomena of thérophysation. Soil analyzes carried out using known methods (Stokes Particle Size Method, Electrometric Method for pH, 1/5 Extract Method for Electrical Conductivity, Bernard Calcium Method for CaCO3, Anne Method for Organic Carbon). The results show a textural diversity;sandy-muddy “Remchi”, sandy “Rachgoun 1 and Rechgoun 2”, not far from Béni-Saf. The low clay content (Remchi: Profile 1: Horizon 1: Clays 10%, Profile 2: Horizon 1: Clays 16%, Profile 3: Horizon 1: Clays 5%, Rechgoun: Profile 1: Horizon 1: Clays 3%, Profile 3: Horizon 1: 2% Clays and Horizon 2: 3% Clays) leads to poor structural stability leading to degradation of the soil surface through erosion. The latter is revealed by the presence of small erosion claws visible on these rough slopes or almost.
文摘This aim of this study is to highlight the critical view of human action and anthropic at the steppe zone of Tlemcen. Therefore, the current paper tends to tackle an analytical study of the dynamics of ecosystems in both states: El-Gor in the south-east and El-Bouihi in the southern-west of Tlemcen. To carry out this study it was necessary to present the bioclimatic context based on weather data to perform bioclimatic syntheses (diagram ombrothermic, climagramme rainfall Emberger). By comparison between old and recent periods (1913-1938) and (1984-2009), respectively, for the region of El-Gor and (1913-1938) and (1970-1990) for the El station-Bouihi, there is a net decrease in rainfall and higher temperatures at the new periods, which means that the study areas are moving towards the driest floors. The interpretation of multidimensional treatments AFC (Factor Analysis of Correspondences) vegetation helps to determine the existing affinities between the different taxa. These biostatistical analyses help to highlight the different factors often responsible for the dynamic regressive most cases.
文摘Relying essentially on human data (social structure, demography, population repartitions, migratory movements, agro-pastural activities), the authors, from their studies, note that these regions are an extension of hamlets and other groups. Highlands gather a small population that seems to settle. Responsible human disturbance (clearings, cultures, urbanization, etc.) modified a large part of the actual state of vegetation structures. The results also show that most of the population is concentrated in the main towns. This concentration causes consumption of pre-forest land and rangelands. The average annual extension can sometimes reach 2.4 Ha. Hamlets, home grouping seem to impose a lifestyle approaching that of centers located in the North. At the bioclimatic level, the results show that the cold thermal variations promote contact between woody vegetation and steppe formations with thermal determinism (formation often in xerophytes thorny pads). Droughts often advocate regressive dynamics of these plant formations which are quite degraded. On the other hand, stressing continuity issues related to human actions, the authors present the floristic composition, detailing the botanical plant species including biological and morphological types. The therophyte type predominates in all areas explored and their percentage can reach 73% in the steppe and 49% in Beni-Snous.