TECTONIQUE ACTIVE ET EVOLUTION DU RELIEF STRUCTURAL DE L’AURES SEPTENTRIONAL

La masse sédimentaire de l’Aurès septentrional (Atlas saharien oriental) a une épaisseur qui dépasse 7000 mètres. Cette masse imposante présente une série à peu près concordante du Jurassique supérieur à l’Eocène moyen, par des alternances de roches cohérentes : de calcaires et dolomies du Portlandien et du Berriasien, calcaires, grès et dolomies de l’Hauterivien, grès du Barrémien, dolomies de l’Aptien, grès de l’Albien, calcaires du Cénomanien, du Turonien, du Maastrichtien et de l’Eocène et des roches meubles; marnes cénomaniennes, santoniennes, campaniennes et éocènes. Ces alternances favorisent le développement d’un relief structural par érosion différentielle. La majorité des éléments de ce relief structural sont conformes à la structure tels que les chaînons et les dépressions orientés NE- SW et qui correspondent à des anticlinaux et des synclinaux pluri kilométriques de direction N 60° E. Par ailleurs, cette diversité est liée aussi à la complexité de l’histoire géologique (héritage morpho structural) d’une part et une évolution Plio Quaternaire très active, caractérisée essentiellement par des mouvements verticaux d’autre part. En fait, le contexte géodynamique en général et la tectonique active en particulier semble jouer un rôle essentiel dans la mise en place de ce relief structural ainsi que son évolution. Cette étude se donne comme objectifs, l’identification et la caractérisation des morpho structures qui favorisent l’évolution et le démembrement de ce relief, jeune et vigoureux

Morpho-structural analysis and mass movements Case study of Oued El Kaïm reservoir dam Nort-East Algeria

peer reviewe

Geomatics-based assessment of the neotectonic landscape evolution along the tebessa-morsott-youkous collapsed basin, Algeria

The neo-tectonic research is interested in the study of the movements of Earth’s crust in recent geological times. It could explain the deformation mechanisms that lead to the structuring of drainage catchments. The Morsott-Tebessa-Youkous (Chabro) collapsed basin corresponds to a subsiding depression framed by brittle structures and filled with thick deposits. Our work aims to unveil the neo-tectonic activity and reconstruct the morphometric evolution of the landscape and the drainage network of the basin. For this task, our investigation applies a quantitative analysis of geomorphic indices extracted from the DEM of the study area. We used a GIS-based approach to compile seven morphometric factors namely Integral Hypsometry (HI), the Sinuosity of mountain fronts (Smf), the Valley Floor width to height ratio (VF), the Asymmetry Factor (AF), Basin Shape index (BS), and the topography (T). All these thematic parameters were processed in a Geo-database to calculate the study area’s Relative Tectonic Activity Index (IRAT) as a result. The IRAT map was categorized into three classes. The result highlighted the distribution of relative tectonic activity in the region and unveiled some unknown faults. It associated the sinuosity of rivers and the deformation of the substratum with active tectonic anomalies. This research work succeeded in drawing up a new scheme of the neo-tectonic activity and morphostructural evolution in the collapsed basin

Landslide Susceptibility Assessment in Constantine Region (NE Algeria) By Means of Statistical Models

The purpose of the present study was to compare the prediction performances of three statistical methods, namely, information value (IV), weight of evidence (WoE) and frequency ratio (FR), for landslide susceptibility mapping (LSM) at the east of Constantine region. A detailed landslide inventory of the study area with a total of 81 landslide locations was compiled from aerial photographs, satellite images and field surveys. This landslide inventory was randomly split into a testing dataset (70%) for training the models, and the remaining (30%) was used for validation purpose. Nine landslide-related factors such as slope gradient, slope aspect, elevation, distance to streams, lithology, distance to lineaments, precipitation, Normalized Difference Vegetation Index (NDVI) and stream density were used in the landslide susceptibility analyses. The inventory was adopted to analyse the spatial relationship between these landslide factors and landslide occurrences. Based on IV, WoE and FR approaches, three landslide susceptibility zonation maps were categorized, namely, “very high, high, moderate, low, and very low”. The results were compared and validated by computing area under Road the receiver operating characteristic (ROC) curve (AUC). From the statistics, it is noted that prediction scores of the FR, IV and WoE models are relatively similar with 73.32%, 73.95% and 79.07%, respectively. However, the map, obtained using the WoE technique, was experienced to be more suitable for the study area. Based on the results, the produced LSM can serve as a reference for planning and decision-making regarding the general use of the land

Unattached carbonate platform evolution across the Aptian–Albian boundary: facies, magnetic susceptibility and sequence stratigraphy in the Constantine area of northeast Algeria

peer reviewedAptian–Albian palaeoenvironments explored in four sections on the Constantine platform, NE Algeria, are identified based on lithology, sedimentary structures, fossil content and microfacies. A mixed unattached carbonate platform is characterised by lagoonal–reefal facies during the Aptian and clastic–carbonate hemipelagic facies during the Albian. The vertical microfacies trend shows a large-scale deepening, locally interrupted by shallowing-upward sequences, especially during the Lower Aptian. Magnetic susceptibility oscillations recorded in the studied sections reflect several factors which influenced the magnetic signal including platform morphology, sedimentary discontinuities, detrital input and sedimentary condensation events. Three major depositional sequences are distinguished and overall indicate a deepening-up trend that generally coincides with the long-term sea-level rise recorded in Cretaceous strata at this time. The correlations between the studied sections demonstrate uplift of the platform and tilting from north to the south during at least the later part of the upper Aptian. Lithostratigraphic correlations and palaeontological assemblages across the Constantinois platform show that the structural units already mapped as overlapping bodies correspond to Albian strata

Solid Waste Management in the Context of a Circular Economy in the MENA Region

Solid waste management in most MENA countries is characterized by lack of planning, improper disposal, inadequate collection services, inappropriate technologies that suit the local conditions and technical requirements, and insufficient funding. Therefore, waste management is mainly limited to collection, transportation, and disposal. As the circular economy has recently been given high priority on the MENA region’s political agenda, all MENA member states are seeking to move away from old-fashioned waste disposal, “waste management”, towards a more intelligent waste treatment, “resource efficiency”. This paper presents a comprehensive overview of national systems for municipal solid waste (MSW) management, and material and energy recovery as an important aspect thereof, in the context of the circular economy in selected countries in the MENA region. Since policy, regulation, and treatment technologies are traditionally connected to MSW management, the focus of this article is twofold. Firstly, it aims to identify the different practices of solid waste management employed in selected MENA region countries and their approaches to embracing the circular economy and, secondly, it examines the extent to which policies and technologies applied play any role in this context. The study revealed that most waste management issues in the countries analyzed appear to be due to political factors and the decentralized nature of waste management with multi-level management and responsibilities. In fact, material and energy recovery in the context of municipal solid waste management does not differ significantly in the countries in the MENA region considered. In most cases, “waste” is still seen as “trouble” rather than a resource. Therefore, a fresh vision on how the solid waste management system can be transformed into a circular economy is required; there is a need for paradigm shift from a linear economy model to a circular-economy model