The aquifers in the M’léta Plain are crucial for supplying drinking water and supporting industrial and agricultural water needs. However, they are facing a pollution risk and environmental degradation. The present study aims to assess the groundwater quality in the M’léta Plain, focusing on its physicochemical properties, statistics of the aquifer, pollution risks, and factors influencing the water mineralisation process. The analysis of 16 samples reveals that the water contains high levels of sulphates and chlorides, often accompanied by sodium, calcium, or magnesium. This suggests two distinct water types or facies: one characterised by sodium chloride or calcium chloride, and the other with calcic or sodic sulphate waters, sometimes including magnesium sulphate. These facies may be attributed to the influence of different formations at the outcrop. Statistical analyses reveal a strong correlation between electrical conductivity and the majority of chemical elements, indicating the impact of freshwater interacting with the underlying rock formations on mineralisation. Some results also show undersaturation of certain minerals. Furthermore, the study evaluates the water's suitability for irrigation in the M’léta Plain in accordance with Richards’ classification.

L’aquifère de Hammam Bradaa se situe au Nord-Est de Guelma à l’Est algérien. Il fait partie du bassin versant de la Seybouse et plus précisément le sous bassin de la moyenne Seybouse qui couvre une superficie de 820 km2. Du point de vue géologique, les formations rencontrées sont en majeure partie carbonatées d’âge Crétacé, avec une couverture récente hétérogène (remplissage d’âge tertiaire). L’objectif est l’identification de la qualité des eaux par l’outil statistique pour ressortir les tendances et par conséquent les groupes chimiques qui caractérisent les eaux de la nappe profonde de Hammam Bradaa. Tout d’abord, l’estimation du coefficient de variation (CV%) indique que la majorité des mesures liées à chaque variable se rapprochent de la moyenne et ne montre pas une grande dispersion, contrairement aux mesures des nitrates qui présentent une grande dispersion autour de la moyenne, ceci peut être expliqué par l’utilisation sélective des engrais chimiques pour l’agriculture des terres exploitées. Par ailleurs, la corrélation simple (matrice de corrélation) et multiple (ACP et C.A.H), mettent en évidence des liens significatifs entre les ions issus de la dissolution des minéraux carbonatés (Mg et HCO3) ainsi que ceux résultants des minéraux évaporitiques (Na et Cl). La conductivité électrique n’indique pas une bonne corrélation avec les ions témoignant ainsi de la faible minéralisation des eaux étudiées. Nous remarquons la bonne concordance entre les résultats de l’analyse statistique et ceux de l’interprétation hydro chimique. 

Several hydrologists recently stated that a large portion of the world’s population will face “water stress” in the coming years due to a variety of factors, including global mismanagement of fresh water near coastal plains, which is still being ignored and has become polluted. The alluvial plain of Wadi El Nil is one of these coastal plains, located in one of the wettest regions of Algeria with an annual rainfall rate of around 1000 mm. To quantify and qualify the water potential and to design a water management policy, a study was conducted using a complex of tools, such as geological, geophysical by electrical methods, hydro-climatic, and hydrogeological, to determine the lithology, geometry, and hydrodynamic characteristics of the aquifer.

The stratigraphical features and palaeoenvironmental conditions of the upper Cenomanian–lower Coniacian carbonates from the northern part of the Aures Range are described for the first time. Four formations have been recognised, namely the Arris, Adahri, Yabous, and Bou Ouali, respectively. Planktonic foraminifera enable us to assign the upper part of the Arris Formation and the lower part of the Adahri Formation to the Middle–Upper Cenomanian (Rotalipora sp. cf. R. cushmani Total Range Zone), the upper part of the Adahri Formation to the Cenomanian–Turonian Transition to the lower Turonian (Whiteinella archaeocretacea Partial Range Zone and Helvetoglobotruncana helvetica Total-Range Zone, respectively), the lower member of the Yabous Formation to the middle Turonian (Marginotruncana sigali Partial Range Zone), and the upper member of the Yabous Formation to the upper Turonian (Marginotruncana schneegansi Partial Range Zone). The Turonian–Coniancian boundary was dated approximately. This biozonation enables a correlation with several upper Cenomanian–lower Coniacian sections outside Algeria, mainly within the Tethyan and Boreal domains. Based on the field data, and microfacies studies, the strata of these formations are arranged into eleven microfacies types (MT 1 to MT 11) that are described in terms of depositional environments, and grouped into three main facies associations (FA 1, FA 2, and FA 3): (i) a deep shelf-basin facies zone; (ii) marginal sand shoals, an open-marine/restricted platform facies zone; and (iii) an outer platform and toe-of-slope/distal slope facies zone. Analysis of the sequence stratigraphy has allowed the recognition of three third-order depositional sequences grouped into two megasequences and correlated to a regional scale.

The thiolliericrinids, although having a stem in the adult stage, are classified as comatulids (Comatulida) that are usually identified as stemless forms. They first appeared in the Bajocian (Middle Jurassic), and their last occurrence is noted in the Hauterivian (Early Cretaceous). Herein we report a thiolliericrinid crinoid from the Aptian of northern Africa (Algeria). This is the youngest thiolliericrinid crinoid ever recorded. Previously, the youngest thiolliericrinid (Thiolliericrinus) came from the Hauterivian (Lower Cretaceous) of France, Germany, Portugal, and Switzerland. This youngest thiolliericrinid has a smooth and irregular centrodorsal with no cirrus socket. The radials are irregular; some of them are variable in size and display no visible basal plates externally. The latter feature is typical of evolutionarily advanced Early Cretaceous thiolliericrinids (e.g., Heberticrinus or Loriolicrinus). Additionally, the present record is also the only representative of thiolliericrinids with a cup strongly oblique on the stem.

This research delves into the geological features of the western section of the Aures Basin, with a primary focus on Djebel Metlili. The geological characteristics span Mesozoic and Tertiary deposits, ranging from the Triassic to the Quaternary epochs. Notably, the higher Cretaceous period stands out for its substantial carbonate-rich sequence. The research relied on geological maps, field observations, core samples, and laboratory analyses, including lithostratigraphic examinations (cross-section) and thin section. Structural features show that is formed by large regular folds of ENE-WSW or E-W direction. Anticlines and synclines are often affected by transverse accidents at the axes of the folds. In its northern part is located immediately south of the Belezma-Batna mountains. Structural analysis highlights significant tectonic disturbances, oriented in a northwest-southeast direction. A detailed lithostratigraphic examination reveals marly formations interspersed with limestone-rich layers containing Inoceramus. The southern part of Dj. Metlili, particularly the Santonian-Campanian series, unveils three distinct meso-transgressive sequences, linked to sea-level fluctuations associated with sedimentary basin subsidence. The studied area exhibits three distinct facies: one characterized by gray phosphate limestone with crisscrossed stratifications and agitated bioclastic sand, another featuring a mollusk-rich bioclastic limestone indicating a turbulent intertidal environment, and a third presenting a clay limestone bank with fine to medium grains and lumachels rich in oysters and gastropods. The associated grainstone texture in the microfacies suggests an internal platform environment marked by dissolution, bioturbation, and ferruginization. This comprehensive exploration provides valuable insights into the geological history of the region, significantly contributing to our understanding of its evolution over time.

The stratigraphic problem of the Jurassic-Cretaceous boundary (JKB) is still the object of a warm international debate. Around this limit, the Upper Tithonian substage has been the subject of significant stratigraphic investigations throughout the Tethyan Realm areas. On the southern Tethys Margin of the Maghreb, our recent works in NE Algeria have revealed sections, where good Upper Jurassic outcrops are considered as promising for the definition of a Global Standard Section and Point (GSSP) for the Jurassic-Ctretaceous boundary. In this line of interest, a high resolution calpionellid biozonation of Upper Tithonian successions from two bed-by-bed sampled key sections in the Aurès (Jebel Azreg) and Aïn Yaghout Mounts (Jebel Toumbaït) of NE Algeria is proposed here for the first time. The Crassicollaria and Calpionella Zone limits, encasing two subzones and six stratigraphic horizons, are identified. Within these sections, calpionellid distribution and resulting biostratigraphic units fit the standards referred to for the Tethyan Realm. The identified marker bioevents and associations confirm the high biostratigraphic potential of calpionellids for the JKB definition in the North Africa Maghrebian Chains. Correlation transects reveal important thickness and facies variations interpreted as the result of a synsedimentary tectonic control implying NW–SE, E-W and NE-SW major faults that led to the individualization of a mozaic of highs and depressions where Upper Tithonian deposits onset. A proposed interpretative model replaces the Upper Tithonian study successions in their regional geodynamic context.

The deterioration of the physico-chemical quality of surface waters in the Algerian Northeast is caused by several factors. Our study aims to fill the knowledge gap on the control of hydro-chemical evolution of surface waters in wetlands. The main focus is on major elements in surface waters of the Skikda region in northeastern Algeria. To address this issue, we received 45 samples during the 09 campaigns conducted during the period of low and high water of the year 2015-2016, distributed over five points, namely the tributary Oued Khemakhem, Oued Bouadjeb, Oued Safsaf, reservoir of the Zerdazas dam and the downstream of the Zerdazas dam. First, we studied the variation of physical elements such as pH and EC. Then, using PCA and FA, we characterized the physicochemical properties of the water to demonstrate the relationship between the elements and the factors controlling the distribution of the major elements and the heavy metals Pb2+, Fe2+ and Sr2+. The specific formula of the dominance of the different concentrations in the surface waters of the study area followed the sequence: Ca-Mg-Na-K and Cl-SO4-HCO3 from which a predominant specific facies emerges on 67% of the samples, is of the chloride and sulfate-calco Magnesian facies.

Lacustrine depositional systems provide a valuable record of palaeoenvironmental conditions since they rely on a delicate balance between accommodation space and water-sediment supply controlled by tectonic activity and climatic conditions. This study presents new sedimentological and micropalaeontological information from the early Miocene lacustrine Oued Tilatou Formation, northeastern Algeria. Based on sedimentary facies and microfossil assemblages, the Oued Tilatou Formation (OTF) is divided into two discrete units, the Lower OTF and the Upper OTF. The Lower OTF is characterised by reddish clay-rich carbonate mudstone containing reworked foraminifera and ostracods interspersed by polymodal clast-supported conglomerates attributed to alluvial deposition. The Lower OTF was deposited under fluvial–palustrine conditions, marked by a notable terrigenous sediment influx. In contrast, the Upper OTF encompasses greenish charophyte-dominated (Sphaerochara sp.) carbonate mudstone interbedded with silty carbonate mudstone, and dolomitic wackestone containing charophyte thalli, several ostracod species, and stromatolites. The dominant ostracod taxa within this interval are Mediocypris sp. cf. M. candonaeformis, indicating freshwater–brackish water conditions. The transition in depositional facies from the Lower OTF to the Upper OTF is interpreted as reflecting changes in the environment from fluvial–palustrine to shallow water lacustrine with fluctuation in freshwater input during the Burdigalian (Early Miocene). This study provides new insights on the interplay between early Miocene climate conditions and the tectonic uplift of the Aurès Massif, and their implications for lacustrine palaeoenvironmental conditions.

The deterioration of the physico-chemical quality of surface waters in the Algerian Northeast is caused by several factors. Our study aims to fill the knowledge gap on the control of hydro-chemical evolution of surface waters in wetlands. The main focus is on major elements in surface waters of the Skikda region in northeastern Algeria. To address this issue, we received 45 samples during the 09 campaigns conducted during the period of low and high water of the year 2015-2016, distributed over five points, namely the tributary Oued Khemakhem, Oued Bouadjeb, Oued Safsaf, reservoir of the Zerdazas dam and the downstream of the Zerdazas dam. First, we studied the variation of physical elements such as pH and EC. Then, using PCA and FA, we characterized the physicochemical properties of the water to demonstrate the relationship between the elements and the factors controlling the distribution of the major elements and the heavy metals Pb2+, Fe2+ and Sr2+. The specific formula of the dominance of the different concentrations in the surface waters of the study area followed the sequence: Ca-Mg-Na-K and Cl-SO4-HCO3 from which a predominant specific facies emerges on 67% of the samples, is of the chloride and sulfate-calco Magnesian facies.

Water resources are facing significant challenges in result of rapidly growing demand, deteriorating quality, and the effects of climate change. Today, water quantity and quality issues have become prevalent in various regions across the globe, affecting both northern and southern territories. Among the sectors reliant on this resource, irrigation stands out as the largest consumer of water. When surface water becomes inaccessible due to insufficient precipitation or other factors, the use of groundwater becomes the only viable alternative for irrigation. The Remila Plain (Khenchela) is located in an endorean watershed in northeastern Algeria and extends over 250 km2 in a synclinal basin filled with water from the Mio-Plio Quaternary - the main aquifer of the region, widely used for irrigation. The aim of this work is to study the hydrochemistry of these waters, as well as the evolution of mineralisation, the identification of the origin of the chemistry, and the suitability of these waters for irrigation. Initial results indicate an evolution of mineralisation in the direction of groundwater flow, with electrical conductivity values varying between 1000μS/cm in the recharge zones, and 2700μS/cm at the outlet. This mineralisation is mainly due to the dissolution of evaporitic minerals and the alteration of silicates. In addition, the various water quality indices used indicate that the water can be used for irrigation without major risk to plants and soils.

Understanding the processes controlling groundwater mineralization is critical for preserving its quality and ensuring sustainable resource management, especially in regions like Naama, Algeria, which rely exclusively on groundwater. T his resource faces severe overexploitation and high salinity due to climatic factors and increasing industrial, agricul tural, and domestic demands, posing significant challenges to its long-term usability. Hydrochemical analyses, inclu ding graphical methods and multivariate statistical tools, were employed to investigate the groundwater chemistry and mechanisms influencing mineralization in the Naama region. The results revealed a relatively homogeneous distribu tion of groundwater samples, categorized into three hydrochemical groups. These groups are primarily dominated by calcium and magnesium chloride and sulfate waters, influenced by the geological characteristics of the region, such as gypsum-saline formations of the Upper Cretaceous and Triassic clay-gypsum-saline diapirs, and further impacted by inverse ion exchange processes. Group 1 is characterized by higher proportions of calcium and magnesium bicarbo nate waters due to the dominance of carbonate formations from the Early Jurassic or Miocene, benefiting from more dynamic recharge zones. Groups 2 and 3 exhibit similar chemical compositions, but Group 3 is distinct for its restricted recharge zones and carbonate formations, leading to the emergence of calcium and magnesium bicarbonate waters. Recharge areas associated with carbonate formations were also vulnerable to anthropogenic pollution. These findings highlight the importance of implementing strict protection measures for sensitive recharge zones to ensure the preser vation of this vital resource in the face of increasing environmental and human pressures.

The increasing pollution of groundwater resulting from population growth and the evolution of agro-industrial activities have become a poses threat to the socio-economic development of the western Algerian region. This study aims to assess the vulnerability and pollution risks of the plain of M’léta and factors that control the transfer of pollutants, and prepare a report on the basis of a thematic map relating to the DRASTIC and DRIST method which is an improvement of the DRASTIC method. Cartographic analysis of the results of the two methods showed the M'léta Plain is characterized by low to high vulnerability, of which almost the entire plain is characterized by low to medium vulnerability. There was 53.75% for the DRASTIC method, while the second rate was 53.06% for the DRIST method, while the high vulnerability is recorded in the northern part of the plain, which swallowed 46.93% for the DRASTIC method, and for the DRIST method, it amounted to 46.24%. The result of the research shows that the preparation of an objective map avoids many risks of pollution and gives possible solutions for any future decision, and that both methods express approximately the same areas with regard to the degree of vulnerability.

Purpose. The neritic aquifer that extends between Hammam Bradaa and El Fedjoudj, despite its faulted and in places karstified structure, due toits capacity and lateral extension represent a strategic resource for the region. Its waters are used for drinking water supply in the neighboring towns: Heliopolis, Guelaat Bousbaa, Nechmaya and El Fedjoudj, as well as in part of the Annaba wilaya. These neritic limestones outcrop at Djebel Debagh and Bouzitoune.

Methods. In order to better study the potential of this aquifer, it is essential to identify its geometry and structure by ana-lyzing the geological data, mechanical drilling data and geophysical data analysis through an electrical survey campaign.Findings. The main results indicate that the study area has identified two important aquifer formations: a formation in the Mio-Plio-Quaternary alluvium consisting of clays, marls, gravel and sand; the second is a deep carbonate aquifer composed of fissured and karstified neritic limestone of the Cretaceous age of variable depth ranging within 50 and 350 m.

Originality. The originality of the study is in the fact that the studied area is characterized by the presence of thick, frac-tured and karstified carbonate formations, which are intensively tectonized and have significant aquifer potential.

Practical implications. The correlation of geological data with geophysical data made it possible to conclude that the stu-died area is a sedimentary basin bounded by faults predominantly oriented to the south-west and north-east, forming a highly fractured unit consisting of horsts and grabens. The significant water potential reservoir is formed essentially by carbonate geological formations, highly fractured with the presence of karst forms represented by resistant horizons.

The region of Chelghoum Laid - Tadjenanet is located in eastern Algeria, in the high plains. This area is characterized by a varied age (Mio-Plio-Quaternary) formations and the human demand is answered by the groundwater hosted into the superficial aquifer of the Mio-Plio-Quaternary formations. However, the overexploitation of this aquifer leads to a drop in the piezometric surface and an increase in salinity. of this aquifer leads to a drop in the piezometric surface and an increase in the salinity of the water. A hydrochemical study using characteristic ratios and statistical tools such as principal component analysis and hierarchical ascending classification, was performed using 28 water samples. Chemical analyzes show that the waters of this aquifer are of the calcium bicarbonate type on the limits of the study area, and calcium sulphate to sodium chloride in the centre. The spatial evolution of chemical water facies is explained by the phenomenon of dissolution and ion exchange between the alkali metals and alkaline earth metals coinciding with the West-East flow direction. The application of the various tools shows that the aquifer is recharged by precipitation at the plains border, where the water acquires its original mineralization from the carbonate formations, and becomes more mineralized in chlorides, sodium and sulphates concentrations in contact with the salt-bearing terrigenous formations of the Mio-Plio-Quaternary. The salinization of the waters seems to be mainly due to the dissolution of gypsum, halite and epsomite. The application of the ascending hierarchical classification and the principal component analysis shows the existence of two groups of water whose salinity increases from the borders towards the center of the plain following the main flow direction.

The region of Chelghoum Laid - Tadjenanet is located in the east of Algeria in the high southern plains of Setif, characterized by a highly vulnerable shallow alluvial aquifer. The vulnerability of groundwater to pollutants is a relative concept, not measurable or dimensional. The nature, quality, and reliability of used data used have a major impact on the correctness of its assessment. Its classification is usually based on the estimation of many more or less essential factors, such as the characteristics of soil and unsaturated zone, the saturated zone, the recharge , the topography and the hydraulic conductivity. The vulnerability of the aquifer to pollution was investigated using two intrinsic vulnerability methods: DRASTIC and susceptibility index (SI). SI method is an adaptation of the DRASTIC specifically design for nitrate-based pollution. The parameters used as input data are, among others, the depth of the groundwater, the soil type, the topographic slope and the groundwater recharge. The validity of the two methods for assessing the vulnerability to nitrates was established by comparing the distribution of these elements in groundwater with the distribution of the various vulnerability classes. GIS techniques were used to implement these methods. Vulnerability maps created using the DRASTIC and SI method’s depict the potential for pollutants to penetrate and spread in these locations depending on the terrain encountered on the surface and the depth of the aquifer. The comparison revealed that the SI technique is the most accurate in the studied alluvial aquifer. The establishment of the pollution vulnerability map highlighted an area of great vulnerability in the center of the plain, reflected by the fragility of the soil and the shallow depth of the water. While the average vulnerability areas are in the center, and east at the periphery of Wadi Rhumel, the rest of the field is slightly vulnerable. The vulnerability and contamination risk maps created for this study are valuable tools for environmental planning and can be used for predictive management of groundwater resources. This case study suggests that the approach may be applicable to other areas as part of efforts to target groundwater management efforts.

Recently, the Guelma region, located northeast of Algeria, has been facing an unusual water shortage. To bypass this situation, a geophysical study using gravity and resistivity has been initiated to enhance the understanding of the geology and hydrogeology of the deep structures of the study area. In order to accomplish this, a residual gravity anomaly map has been constructed by removing from the Bouguer anomaly map a regional gravity gradient using the upward continuation technique. For the purpose of validating the Vertical Electrical Sounding(VES) interpretation, two soundings were conducted near boreholes with known lithology. The Hammam Bradaa deep aquifer of the Guelma region is composed of limestones that belong to the Constantine neritic domain. The Constantine neritic domain is covered by thrust nappes and outcrops in some places of the study area as tectonic windows. The exact geometry such as depth and lateral extent of the aquifer are not well known. Since limestones are characterized by high densities and resistivities relative to the host rock, the combining of gravity and VES was able to accurately map their extension among the other lithologies composing the geological section. Multiscale edge detection of gravity data known as "worms" made it possible to highlight the principal lineaments across the study area which may contribute to the recharge of the Hammam Bradaa aquifer. The 3D Gravity inversion enabled the mapping of the spatial configuration of limestones that are characterized by positive gravity contrast relative to the host rocks. A vertical density slice extracted from the 3D gravity inversion, running from north to south, reveals a significant thickness of limestone beneath Hammam Bradaa which suggests a strong potential for groundwater resources. The geo-electric section, constructed from the interpretation of VES data and calibrated with well lithology, enabled the mapping of the depth to the top of limestone beneath conductive alluvium and marls.

The region of Chelghoum Laid - Tadjenanet is located in the east of Algeria in the high southern plains of Setif, characterized by a highly vulnerable shallow alluvial aquifer. The vulnerability of groundwater to pollutants is a relative concept, not measurable or dimensional. The nature, quality, and reliability of used data used have a major impact on the correctness of its assessment. Its classification is usually based on the estimation of many more or less essential factors, such as the characteristics of soil and unsaturated zone, the saturated zone, the recharge , the topography and the hydraulic conductivity. The vulnerability of the aquifer to pollution was investigated using two intrinsic vulnerability methods: DRASTIC and susceptibility index (SI). SI method is an adaptation of the DRASTIC specifically design for nitrate-based pollution. The parameters used as input data are, among others, the depth of the groundwater, the soil type, the topographic slope and the groundwater recharge. The validity of the two methods for assessing the vulnerability to nitrates was established by comparing the distribution of these elements in groundwater with the distribution of the various vulnerability classes. GIS techniques were used to implement these methods. Vulnerability maps created using the DRASTIC and SI method’s depict the potential for pollutants to penetrate and spread in these locations depending on the terrain encountered on the surface and the depth of the aquifer. The comparison revealed that the SI technique is the most accurate in the studied alluvial aquifer. The establishment of the pollution vulnerability map highlighted an area of great vulnerability in the center of the plain, reflected by the fragility of the soil and the shallow depth of the water. While the average vulnerability areas are in the center, and east at the periphery of Wadi Rhumel, the rest of the field is slightly vulnerable. The vulnerability and contamination risk maps created for this study are valuable tools for environmental planning and can be used for predictive management of groundwater resources. This case study suggests that the approach may be applicable to other areas as part of efforts to target groundwater management efforts.

Groundwater recharge is widely recognized as being the most important parameter for the sustainable management of water resources. In semiarid environments, groundwater recharge can be quantified using the piston displacement method (PDM). From a single soil sampling campaign, the PDM relies on linking the deeper vadose zone soil pore water stable isotope composition (δ²H_H2O and δ¹⁸O_H2O) to the local meteoric water line (LMWL). However, the isotopic composition of precipitation changes seasonally, influencing the water isotope composition of the vadose zone over time. Thus, it is important to test whether the PDM is sensitive to seasonal soil sampling and whether the assessed recharge rate is independent of the time of sampling. This study investigates the effect of seasonal soil sampling on the distribution of vadose zone stable isotope composition to determine whether the sampling time influences the estimate of recharge rate from PDM. Soil samples were obtained along vertical profiles through the vadose zone in a semiarid region during the spring, summer, and autumn seasons. Specifically, the δ²H_H2O and δ¹⁸O_H2O of the soil pore water were determined along vertical profiles, and the PDM was applied to quantify the annual recharge. The δ²H_H2O and δ¹⁸O_H2O values range from −7.3 to −3.5 ‰ and from −54.4 to +7.41 ‰, respectively, and plot along a continuum with a slope less than the LMWL. Samples from deeper in the vadose zone profile had distinct ranges in isotopic composition between the three soil sampling campaigns, with isotopic composition of spring sampling dominated by lower values and those from autumn with higher values. Despite these differences, the resulting annual recharge rates from the different sampling campaigns are comparable (1.5 to 2 % of annual precipitation). Even though the pore water isotopic composition changed over time, the shift between the deeper vadose zone isotopic compositions and the LMWL remained relatively constant, leading to a similar recharge estimate over time. Therefore, the PDM-based recharge assessment in the tested semiarid environment is independent of the sampling time, which indicates that sampling for assessing groundwater recharge can be undertaken during any season.

This paper presents a gravimetric study aimed at analyzing the geological structure and hydrogeological potential of the Télidjene basin in eastern Algeria. The data used are based on the EGM2012 gravimetric model and have been corrected using the International Gravimetric Bureau (BGI). Bouguer anomalies were calculated using spherical harmonic coefficients and underwent topographic corrections. The upward continuation method was used to attenuate shortwavelength anomalies and separate regional and residual components. Spectral analysis allowed for determining the average depths of geological formations. The results obtained from the gravimetric processing provided valuable information on the geological structure and hydrogeological potential of the study area and enabled the creation of a structural map illustrating the fault system responsible for the structuring of the study area. This map serves as a highly useful document for guiding future hydrogeological research in the study area.