This paper aims to offer an improved version of the new composite drought monitoring index (CDMI) and to test its applicability in the context of Tensift watershed in Morocco. A synergistic approach incorporating the remote sensing techniques, hydrometeorological data, simulated data and agricultural statistics was used for this purpose. After assessing the performance of CDMI, estimated Soil Moisture Anomaly Indicator (ISMA) was processed, validated and incorporated to the composite model. Random Forest algorithm was used to determine the weight of composite model components. Apart from comparative mapping, Pearson's correlation statistical analysis, linear regression and dependency tests were used to assess the performance of the improved composite model (CDMIa_RF). The result show that CDMIa_RF is better correlated with several indices such as: the Standardized Precipitation Index (SPI), (R2=0.74); Hydrological Drought Index (R2=0.70); grain productivity (R2=0.70), CDMI (R2=0.95), Vegetation Health Index (VHI), (R2=0.87), and Normalized Vegetation Supply Water Index (NVSWI), (R2= 0.85).

The concepts of Digital Twin has been recently introduced, it refers to functional connections between a complex physical system and its high-fidelity digital replica. Digital Twin process workflow is proposed in case of Mohammed VI Bridge modeling in Morocco. The current maintenance of a road infrastructure is based on a manual inspection and a system based on traditional tools. Aging infrastructures require a new approach to maintenance in terms of inspection, bridge maintenance system, simulation and systematic evaluation. This system now exists and is called the Digital Twin. Digital Twin can be thought of as a virtual prototype in service that changes dynamically in near real time as its physical twin changes. An urban infrastructure digital twin is a virtual instance of his physical twin that is continuously updated with multisource, multisensor and multitemporal data that can be used for monitoring, simulating and forecasting any potential problem that may appear in the structure and proposing planning for repair and maintenance of health status throughout the life cycle of this infrastructure. This work presents a general vision and a justification for integrating DT technology with geospatial data. The paper examines the benefits of integrating 3D GIS data acquired by automated mobile mapping (MMS) workflows for modeling the reality of a major bridge infrastructure in Morocco. This allowed to study the future performance of this bridge structure on virtual twin structures under different environmental conditions. Cloud point data are acquired by a Mobile Mapping System on Mohammed VI Bridge and converted in BIM model by a scan to BIM process and is integrated in a GIS and BIM virtual environment and shows the efficiency of volumetric auscultation in terms of surface flatness and distortion inspection. This project provides a new bridge maintenance system using the concept of a Digital Twin. This digital model is a platform that allows to collect, organize and share the maintenance history of this important road infrastructure in Morocco.

The Bouregreg watershed is located to the north-western center of Morocco, characterized by a semi-arid climate. It covers a total area of approximately 10 000 km2. This basin is a very sensitive area to water erosion. This causes the degradation of its vegetation cover and its land. The most sensitive and poorly protected soils erode much more easily and lose their fertility.The objective of this work is to quantify soil losses by water erosion in the Bouregreg watershed using the Revised Universal Loss Equation (RUSLE) and Geographic Information Systems. The average annual rate of soil erosion in the Bouregreg watrershed are estimated at 20 t ha−1 yr−1. The spatial distribution map of soil erosion show that 71 % of the total area has low risk of soil erosion (<3 t ha−1 yr−1), while 28 % of the study area shows moderate to high risk of erosion (20–60 t ha−1 yr−1). Areas of very high risk of erosion are also present in some sectors of the watershed covering 1 % of the total surface.

Imlili Sebkha is a stable and flat depression in southern Morocco that is more than 10 km long and almost 3 km wide. This region is mainly sandy, but its northern part holds permanent water pockets that contain fauna and flora despite their hypersaline water. Google Earth Engine (GEE) has revolutionized land monitoring analysis by allowing the use of satellite imagery and other datasets via cloud computing technology and server-side JavaScript programming. This work highlights the potential application of GEE in processing large amounts of satellite Earth Observation (EO) Big Data for the free, long-term, and wide spatio-temporal wet/dry permanent salt water cavities and moisture monitoring of Imlili Sebkha. Optical and radar images were used to understand the functions of Imlili Sebkha in discovering underground hydrological networks. The main objective of this work was to investigate and evaluate the complementarity of optical Landsat, Sentinel-2 data, and Sentinel-1 radar data in such a desert environment. Results show that radar images are not only well suited in studying desertic areas but also in mapping the water cavities in desert wetland zones. The sensitivity of these images to the variations in the slope of the topographic surface facilitated the geological and geomorphological analyses of desert zones and helped reveal the hydrological functions of Imlili Sebkha in discovering buried underground networks.

This study aims to present a technique that combines multi-sensor spatial data to monitor wetland areas after a flash-flood event in a Saharan arid region. To extract the most efficient information, seven satellite images (radar and optical) taken before and after the event were used. To achieve the objectives, this study used Sentinel-1 data to discriminate water body and soil roughness, and optical data to monitor the soil moisture after the event. The proposed method combines two approaches: one based on spectral processing, and the other based on categorical processing. The first step was to extract four spectral indices and utilize change vector analysis on multispectral diachronic images from three MSI Sentinel-2 images and two Landsat-8 OLI images acquired before and after the event. The second step was performed using pattern classification techniques, namely, linear classifiers based on support vector machines (SVM) with Gaussian kernels. The results of these two approaches were fused to generate a collaborative wetland change map. The application of co-registration and supervised classification based on textural and intensity information from Radar Sentinel-1 images taken before and after the event completes this work. The results obtained demonstrate the importance of the complementarity of multi-sensor images and a multi-approach methodology to better monitor changes to a wetland area after a flash-flood disaster.

Highlights: - Development an open source application of soil erosion risk DUSLE (Desktop Universal Soil Loss Equation). -. Predict the average soil loss.

Structural study of the recent deformations of the Eç-çour area, located on the southern slope of the massif ancien of the High Atlas, has allowed us to obtain the following results: (1) In the Ait Maghlif plateau, on the northern border of the Siroua volcanic massif, the N-S structures that are bounded by the reverse Imini fault to the north and the left-lateral Tawyalt−Agandiy fault in the south, correspond to forced folds on reverse faults and related folds related to a NW-SE compression, some of which were former normal syndepositional faults that were active in Cretaceous times; an intermediate phase corresponding to a NNE-SSW compression which is thought to have triggered the Siroua volcanism; (2) along de South Atlas Fault, the recent tectonism is expressed by folding and faulting of several Quaternary alluvial fans, some of which bear reverse/dextral slickensides.

The Taza-Guercif Basin is on the southern margin of the former Rifean Corridor, one of the major Miocene marine connections between the Atlantic Ocean and Mediterranean prior to the onset of the Messinian Salinity Crisis. As the first basin in the corridor to emerge during corridor closure, the basin is a key location for understanding this major marine event. To constrain the mechanisms for corridor closure, we contribute 499 zircon U-Pb crystallization ages and 98 zircon fission-track (ZFT) cooling ages from the stratigraphy of the Taza-Guercif Basin. The U-Pb age signature of the Taza-Guercif Basin is dominated by Pan-African (700–560 Ma) and West African craton (2200–1800 Ma) ages, and contains a significant abundance of Mesoproterozoic ages recently characterized in Mesozoic sediments from the Rif and Middle Atlas mountains. The ZFT ages record a significant Triassic-centered cooling population (275–150 Ma), well-defined Variscan (ca. 330 Ma) and post Pan-African (498 Ma) cooling peaks, and a scattering of Precambrian cooling ages. The cooling ages suggest a source in the Middle Atlas; this is consistent with the U-Pb crystallization ages. Furthermore, there is no discernable change in either the U-Pb or ZFT populations during basin emergence. Together, these observations suggest that the Middle Atlas mountains were a consistent source of sediment to the Taza-Guercif Basin and played a significant role in the closure of the Taza-Guercif Basin and possibly the Rifean Corridor.

Despite the presence of a deep history of continental evolution from Archean to Recent and a wealth of outcrop, existing studies of detrital zircon geochronology in Morocco are limited, focused mostly in the Cambrian and Neoproterozoic Pan-African exposures in the Anti-Atlas belt. We broaden the use of this tool by surveying the detrital zircon geochronology of three stratigraphic units from three distinct Mesozoic terranes: the Tisiren unit of the Maghrebian flysch domain, the Ketama unit of the Intrarif, and the Bou Rached sandstones of the Middle Atlas Mountains. Samples were analyzed for zircon U-Pb ages using laser-ablation inductively coupled plasma mass spectrometry, and zircon fission-track (ZFT) ages were analyzed using the emerging technique of scanning electron microscope high-density fission-track analysis. In total, 259 U-Pb ages are presented, along with 60 ZFT ages. U-Pb ages reveal dominant Pan-African (Cryogenian-Ediacaran) and West African cratonic (Paleoproterozoic) signatures that are typical of northwest Africa. All samples also include significant Mesoproterozoic U-Pb populations that are hitherto unknown in Morocco and scarce in North Africa. Proposed scenarios for the provenance of these zircons include delivery to Morocco from the Amazonian craton or the African Volta basin during Ordovician glaciation and/or delivery from Avalonian terranes during the Variscan orogeny. The Bou Rached sandstones contain a significant Ordovician-Devonian U-Pb population not found in the other samples and are of an age without a viable source currently dated in Morocco. An Avalonian source is likewise suggested for these Ordovician-Devonian ages. The Ketama and Tisiren units have comparable U-Pb ages, but their preliminary ZFT cooling age distributions differ, lending support to the idea that different source regions are required for the two domains.

Les paysages du bassin versant du Bouregreg ont evolue sous l'effet direct et indirect de facteurs climatiques, pendant les episodes de secheresses qui ont touche le pays depuis le debut des annees 1980. Dans ce contexte, cette etude evalue la dynamique de l'occupation du sol sur l'ensemble du bassin versant (9970 km2) entre 1985 et 2007 a partir de donnees satellitaires (images Landsat). La methodologie s'appuie sur l'utilisation de la teledetection et des SIG pour analyser la dynamique des grandes classes d'occupation du sol de la zone d'etude. Ces classes concernent les parcelles agricoles, la vegetation naturelle, les sols nus, les surfaces en eau et les zones urbanisees. Les cartes d'occupation du sol ont ete produites a partir d'une classification supervisee par maximum de vraisemblance. Elles permettent de mettre en evidence une baisse substantielle du couvert forestier au detriment d'une expansion de cultures cerealieres. En outre, les sols denudes connaissent-ils une augmentation notable de 1985 a 2007. Enfin, le bassin est marque par une urbanisation continue de la zone littorale. Les observations comparees aux statistiques agricoles confirment cet etat de fait. Aussi, l'analyse des rendements des cereales permet-elle de constater une degradation de la productivite des sols. La chute des rendements est egalement en forte correlation avec l'evolution de la pluviometrie, dans un bassin ou l'agriculture est essentiellement pluviale. (Resume d'auteur)

In North Africa, the filling of dams by sediments is a major problem. Relationships with the evolution of land use and climate change are poorly understood. The hypothesis is that changes in land use and increasing agricultural pressure, associated with a sustained decrease in rainfall, fragilize soils and make them more susceptible to erosion. Two major watersheds are studied in the framework of SIGMED (spatial approach of the impact of agricultural activities on sediment transport and water resources in large catchments): Wadi Bouregreg in Morocco and Wadi Mina in Algeria. One of the objectives is to follow the evolution of land-cover to identify sensitive areas and compare with sedimentation in dams. Erosion from the immediate banks of the dams could be a major source of sediment in reservoirs and be the focus area for operations of protection and restoration of vegetation, preventing the risk of filling.

Bouregreg watershed belongs to the favourable ecological zone of Morocco's central northwest plateau. This watershed is a rainfed area that is marginal for cereal cutivation. Also, this zone belongs to the favourable pastoral areas of that kingdom. The country, like the whole of the Maghreb, since the mid-1970s and beginning of the 1980s, has had more random rainfall conditions. These rainfall changes are marked by substantial declines and greater recurrence of droughts. This study highlights the nature of the spatio temporal phytomass dynamics in this rainfall crisis, in the watershed from 1982 to 2009. From statistics of time series of NDVI pixel values of NOAA images for this period, the study finds a sharp decline in vegetation during the summers. But regression analysis between the rainfall and vegetation finds instead an impact of the rainfall on the wet seasons. It leads to the conclusion that factors other than precipitation are responsible for the sharp decline in vegetation.

The Tafilalt region, located at the eastern end of the Anti-Atlas chain in Morocco, was shaken on 23 and 30 October 1992 by two moderate earthquakes of magnitude mb ∼ 5 and intensity ∼ VI MSK64, which caused two deaths and great damage in the area between Erfoud and Rissani. The review of data available on the seismic crisis allowed us to improve the knowledge on the macroseismic, instrumental and source parameters of the earthquakes. The main results of the present study are: (1) location of the epicentres with the help of data from a close portable network allowed us to propose new epicentral coordinates at 31.361° N, 4.182° W (23 October) and 31.286° N, 4.347° W (30 October); both events have focal depths of 2 km; (2) the shock of 30 October was followed by a series of 305 aftershocks, most of which were located west of Rissani; the 61 best-constrained events had focal depths of 5 to 19 km and magnitudes 0.7 to 3; (3) the largest damage was located in an area between the two epicentres within the Tafilalt valley and was probably amplified by site effects due to the proximity of the water table within the Quaternary sediments; (4) focal mechanisms of the main events correspond to strike-slip faulting with fault planes oriented N–S (left lateral) and E–W (right lateral); the only mechanism available for the aftershocks also corresponds to strike-slip faulting; (5) spectral analysis shows that the scalar seismic moment (Mo) of the first event is slightly larger than the second; the corresponding values of Mw are 5.1 and 5.0, respectively; (6) the dimensions of the faults for a circular fault model are 7.7 ± 1.4 and 7.4 ± 1.2 km, respectively; the average displacement is 4 cm for the first event and 3.7 cm for the second; the stress drop is 0.4 and 0.3 MPa, respectively, in agreement with standard values; (7) the Coulomb Stress test performed for both earthquakes suggests a relationship between both events only when the used location is at the limit of the horizontal uncertainty; (8) finally, the occurrence of these shocks suggests that the Anti-Atlas is undergoing tectonic deformation in addition to thermal uplift as suggested by recent publications.

En este trabajo se estudia el conjunto de manantiales karsticos que drenan el macizo carbonatico del Haouz (Cordillera del Rif, Marruecos). En primer lugar, se anliza el contexto geologico, caracterizado por una compleja disposicion estructural de 4 conjuntos litologicos implicados: la Dorsal, el Complejo Sebtide, el Complejo Ghomaride y el Flych. La estructura general consiste en un conjunto de escamas tectonicas alargadas en direccion N-S, con estructura en abanico, cortadas por fallas de salto en direccion. Como consecuencia de ello, el sistema hidrogeologico del Haouz se encuentra muy compartimentado, con un elevado numero de surgencias que bordean los materiales carbonaticos y que se encuentran asociadas en su mayoria a accidentes tectonicos. Se identifican 3 sectores hidrogeologicos (Jebel Musa, Fahs el Mahr-Annassar y Jebel Darsa) en funcion de la posicion geografica de los afloramientos y caracteristicas litologicas y/o estructurales. Las diferencias encontradas en la composicion hidroquimica e isotopica de los distintos manantiales se interpreta basicamente como consecuencia de diferencias en la litologia (calizas, dolomias y evaporitas), la longitud del flujo y tiempo de residencia de las aguas en el acuifero, la altitud del area de recarga y el grado de fracturacion de los materiales carbonaticos.