Abdelhadi El Ouahidi

This article presents preliminary results from a geoarchaeological and geomorphological investigation of Amazigh agricultural landscapes in the western Anti Atlas (Morocco). Fieldwork followed two main survey transects across contrasting physiographic units, including external plateaus, synclinal depressions, the Kerdous inlier, and spring fed inner oases. The survey documented a wide range of landesque and associated agrarian features, including agricultural terraces, check dams, cisterns, threshing platforms, settlements, and fortified collective granaries (igoudar). Their distribution shows a strong relationship with geology, slope morphology, sediment availability, water circulation, and settlement organisation. On plateaus and synclines, agrarian structures are closely associated with igoudar, settlements, runoff control, and crop processing areas. Within the Kerdous inlier, extensive terracing occurs across rugged slopes, while inner oases combine spring fed agroforestry on valley floors with dense terracing along basin margins. These results suggest that the western Anti Atlas should be understood as a long term engineered socio ecological landscape shaped by Amazigh collective strategies for soil conservation, water management, cultivation, storage, and territorial protection.

Une évaluation approfondie des géo-ressources du plateau de Lakhssas et du massif d’Ifni a été menée en vue d’optimiser l’implantation de carrières. La méthodologie mise en œuvre repose sur la caractérisation géomécanique des affleurements rocheux, couplée à une analyse spatiale par Système d’Information Géographique (SIG). Un échantillonnage représentatif a permis de réaliser des essais géotechniques en laboratoire. Les résultats ont été classifiés selon les normes (Marocaines et Européenne). L’intégration de ces données au SIG a généré une cartographie géotechnique identifiant cinq classes de potentiel d’exploitation: Haut, Moyen, Bas, Très Bas et Nul. L’analyse spatiale démontre qu’environ 72 % de la zone d’étude affiche un potentiel élevé. Cette approche combinant données de terrain et géomatique offre un outil d’aide à la décision performant pour la gestion durable des ressources extractives et la préservation du patrimoine géologique, constituant un cadre méthodologique rigoureux pour le développement responsable du secteur.

This paper aims to characterize the state of land use and its spatio-temporal evolution of the two representative sites: Greater Agadir (Morocco) and the eastern periphery of Algiers (Algeria). To fulfill this objective, we applied the supervised classifications and grid method on a series of satellite images, “Landsat-TM and ETM” from 1988- 2005, and aerial photos and orthophotos. This processing is supported by surveys and field data. Then we produced maps to obtain quantitative data on the spatiotemporal evolution of land cover and the assessment of agricultural land consumption. We concluded that the study areas experienced poorly managed urbanization which has encroached on half of the agricultural area during the period 1987-2005 with the loss of more than 12,000 ha at a rate of 700 ha/year.

The purpose of this paper is to identify, quantify and delineate the areas with suitable aggregate resources in the Precambrian massif of Ifni and the limestone plateau of Lakhssas (southwest Morocco). To fulfill this objective, a study was undertaken on the geotechnical parameters of the various geological outcrops of the region based on the analysis of 42 rock samples (carbonate, magmatic, detritic and volcano-detritic). Initially, we subjected these samples to a series of laboratory tests (impact resistance (L.A), wear resistance (MDE), density, porosity, absorption), to classify them according to geotechnical standards. Then, a geospatial database was created, to exploit these geotechnical data, from a geographical information system (GIS) to produce various thematic maps. Based on the results of this study, all geotechnical classes according to the standards (A to E for the European standard and 1A to 6D for the Moroccan standard) are present with good to very good geomechanical properties (L.A between 12% and 35%, MDE between 5% and 30%). This classification allowed us to use GIS to identify and quantify potential areas for exploitation by assigning five categories of geotechnical suitability levels (high (4), medium (3), low (2), very low (1) and others (0)) and to show that approximately 72% of the study area belongs to the categories high, medium and low. The combination of laboratory results and GIS has allowed us to carry out geotechnical mapping that will be used by regional authorities and actors for good management of the field of quarrying to rationalize the national natural heritage.