Some Aspects of Climate Variability and Increasing Aridity in Central Morocco over the Last Forty Years: Case of Tensift Basin (Marrakech-Morocco)

Morocco, due to its location in the Mediterranean circumference, is vulnerable to present and future climate variability and climate change. Its surface water resources are becoming ever more limited and difficult to exploit. It might be expected that the warming of the hot season and drought would result in an increase in arid and semi-arid regimes of the region. In this context, we are interested in the evolution of aridity through climate indexes, including precipitation, temperature and evapotranspiration over the last 40 years in the Tensift watershed (central Morocco). As preliminary results, in the Tensift basin, the temperature became higher during the last two decades. It diminishes paradoxally towards mountainous areas. A slight decrease of precipitation has been noticed in the foothill regions of the High Atlas and near the Haouz plain. The study of aridity evolutions by the aridity index of De Martonne and aridity index of UNEP takes into account respectively the ratio between the mean annual precipitation (P) and temperature (T) and the relationship between annual precipitation and evapotranspiration. Generally, the aridity is decreasing from downstream to upstream of the study area. But during the past two decades, the region of the Tensift knew a subtantial augmentation in arid land regime may be due to global warming and reduced precipitation measured. Typically, there is a coherence between UNEP index and the index of the De Martonne from point of view of increasing aridity, which adds robustness to the result. Keywords: Tensift watershed, De Martonne’s aridity index, UNEP index, aridity, spatial variability

Techniques to Detect DoS and DDoS Attacks and an Introduction of a Mobile Agent System to Enhance it in Cloud Computing

Security in cloud computing is the ultimate question that every potential user studies before adopting it. Among the important points that the provider must ensure is that the Cloud will be available anytime the consumer tries to access it. Generally, the Cloud is accessible via the Internet, what makes it subject to a large variety of attacks. Today, the most striking cyber-attacks are the flooding DoS and its variant DDoS. This type of attacks aims to break down the availability of a service to its legitimate clients. In this paper, we underline the most used techniques to stand up against DoS flooading attacks in the Cloud

Hydrological assessment of different satellite precipitation products in semi-arid basins in Morocco

In data-sparse regions and in developing countries such as Morocco, where flooding has serious socio-economic impacts, satellite-based precipitation products open new possibilities for monitoring and modelling water resources and floods. The objective of the study is to explore the possibility of using satellite precipitation products (SPPs) with hydrological models (CREST and MISDc) over 9 basins in Morocco. This work provides a hydrological assessment of three SPPs that have demonstrated good capabilities in reproducing precipitation over different basins in Morocco (GPM IMERG – PERSIANN CDR (PERCDR) and CHIRPS). The two hydrological models are coupled with a stochastic calibration method to provide the different ranges of uncertainties. In addition, we investigate the ability of SPPs on reproducing the November 2014 flood event that affected a large part of Morocco. The results indicated that, in calibration, both hydrological models provided similar performance to reproduce river discharge with observed precipitation or PERSIANN CDR. In validation, the combination of the MISDc model with PERSIANN CDR performed the best, notably allowing a good simulation of the flood hydrographs during the November 2014 event. Future analysis of relationships between SPPs, basin properties, and hydrological modelling technique will allow to find the appropriate combination for different application purposes

Genèse et propagation des crues en milieu sub-aride : exemple de l'Oued Souss (Maroc) (Flood's genesis and propagation in sub-arid environment as exemplified by Oued Souss (Morrocco))

The Souss basin is situated in sub-saharan Morrocco, whose characteristics are an extreme aridity in summer, an important irregularity of river's regime and a great spatio-temporal varriability of rains. The floods of Oued Souss appear suddenly in the cold season and are commonly brief. Their violence and great speed of spreading are typical of floods in the arid and sub-arid zone.Le bassin du Souss se situe dans une zone du Maroc sub-saharien où interfèrent une aridité accrue en été, une irrégularité importante du régime de l'oued et une grande variabilité spatio-temporelle des pluies. Les crues du Souss apparaissent en saison froide de façon brutale et sont en général de courte durée. Leur violence et leur grande vitesse de propagation forment un trait marqué des crues en domaine aride et sub-aride.Elmehdi Saidi Mohamed. Genèse et propagation des crues en milieu sub-aride : exemple de l'Oued Souss (Maroc) (Flood's genesis and propagation in sub-arid environment as exemplified by Oued Souss (Morrocco)). In: Bulletin de l'Association de géographes français, 71e année, 1994-1 ( janvier). Approches du paysage / Communications diverses, sous la direction de Bernard Bomer. pp. 94-111

Techniques to Detect DoS and DDoS Attacks and an Introduction of a Mobile Agent System to Enhance it in Cloud Computing

Security in cloud computing is the ultimate question that every potential user studies before adopting it. Among the important points that the provider must ensure is that the Cloud will be available anytime the consumer tries to access it. Generally, the Cloud is accessible via the Internet, what makes it subject to a large variety of attacks. Today, the most striking cyber-attacks are the flooding DoS and its variant DDoS. This type of attacks aims to break down the availability of a service to its legitimate clients. In this paper, we underline the most used techniques to stand up against DoS flooading attacks in the Cloud

Comparison of High-Resolution Satellite Precipitation Products in Sub-Saharan Morocco

Precipitation is a crucial source of data in hydrological applications for water resources management. However, several regions suffer from limited data from a ground measurement network. Remotely sensed data may provide a viable alternative for these regions. This study aimed to evaluate six satellite products (GPM-F, CHIRPS, PERSIANN-CCS-CDR, GPM-L, GPM-E and PDIR-Now), with high spatio-temporal resolution, in the sub-Saharan regions of Morocco. Precipitation observation data from 33 rain-gauge stations were collected and used over the period from September 2000 to August 2020. The assessment was performed on three temporal scales (daily, monthly and annually) and two spatial scales (pixel and basin scales), using different quantitative and qualitative statistical indices. The results showed that the GPM-F product performed the best, according to the different evaluation metrics, up to events with 40 mm/day, while the GPM near real-time products (GPM-E and GPM-L) were better at detecting more intense rainfall events. At the daily time scale, GPM-E and GPM-L and, on monthly and annual scales, CHIRPS and PERSIANN-CCS-CDR, provided satisfactory precipitation estimates. Moreover, the altitude-based analysis revealed a bias increasing from low to high altitudes. The continental and mountainous basins showed the lowest performance compared to the other locations closer to the Atlantic Ocean. The evaluation based on the latitudes of rain gauges showed a decrease of bias towards the most arid zones. These results provide valuable information in a scarcely gauged and arid region, showing that GPM-F could be a valuable alternative to rain gauges

Comparison of High-Resolution Satellite Precipitation Products in Sub-Saharan Morocco

Precipitation is a crucial source of data in hydrological applications for water resources management. However, several regions suffer from limited data from a ground measurement network. Remotely sensed data may provide a viable alternative for these regions. This study aimed to evaluate six satellite products (GPM-F, CHIRPS, PERSIANN-CCS-CDR, GPM-L, GPM-E and PDIR-Now), with high spatio-temporal resolution, in the sub-Saharan regions of Morocco. Precipitation observation data from 33 rain-gauge stations were collected and used over the period from September 2000 to August 2020. The assessment was performed on three temporal scales (daily, monthly and annually) and two spatial scales (pixel and basin scales), using different quantitative and qualitative statistical indices. The results showed that the GPM-F product performed the best, according to the different evaluation metrics, up to events with 40 mm/day, while the GPM near real-time products (GPM-E and GPM-L) were better at detecting more intense rainfall events. At the daily time scale, GPM-E and GPM-L and, on monthly and annual scales, CHIRPS and PERSIANN-CCS-CDR, provided satisfactory precipitation estimates. Moreover, the altitude-based analysis revealed a bias increasing from low to high altitudes. The continental and mountainous basins showed the lowest performance compared to the other locations closer to the Atlantic Ocean. The evaluation based on the latitudes of rain gauges showed a decrease of bias towards the most arid zones. These results provide valuable information in a scarcely gauged and arid region, showing that GPM-F could be a valuable alternative to rain gauges

Rainfall Variability and Teleconnections with Large-Scale Atmospheric Circulation Patterns in West-Central Morocco

Morocco is characterized by a semi-arid climate influenced by the Mediterranean, Atlantic, and Saharan environments, resulting in high variability in rainfall and hydrological conditions. Certain regions suffer from insufficient understanding concerning the spatiotemporal patterns of precipitation, along with facing recurrent periods of drought. This study aims to characterize the current trends and periodicities of precipitation in west-central Morocco at monthly and annual scales, using data from six rain gauges. The link between monthly precipitation and both the North Atlantic Oscillation (NAO) and the Western Mediterranean Oscillation (WeMO) indices was tested to identify potential teleconnections with large-scale variability modes. The results reveal interannual variability in precipitation and climate indices, while showing decreasing insignificant trends in annual precipitation. On a monthly scale, temporal precipitation patterns are similar to the annual scale. Furthermore, a remarkably robust and significant component with a periodicity of 6–8 years emerges consistently across all monitoring stations. Intriguingly, this band exhibits a more pronounced presence on the plains as opposed to the mountainous stations. Additionally, it is noteworthy that the NAO modulated winter precipitation, whereas the influence of the WeMO extends until March and April. This mode could be linked to the fluctuations of the WeMO from 1985 to 2005 and, subsequently, to NAO variations. Indeed, this is consistent with the strong significant correlations observed between rainfall and the NAO/WeMO. This study serves as a baseline for future research aiming to understand the influence of climate indices on rainfall in the North African region

Spatiotemporal Assessment and Correction of Gridded Precipitation Products in North Western Morocco

Accurate and spatially distributed precipitation data are fundamental to effective water resource management. In Morocco, as in other arid and semi-arid regions, precipitation exhibits significant spatial and temporal variability. Indeed, there is an intra- and inter-annual variability and the northwest is rainier than the rest of the country. In the Bouregreg watershed, this irregularity, along with a sparse gauge network, poses a major challenge for water resource management. In this context, remote sensing data could provide a viable alternative. This study aims precisely to evaluate the performance of four gridded daily precipitation products: three IMERG-V06 datasets (GPM-F, GPM-L, and GPM-E) and a reanalysis product (ERA5). The evaluation is conducted using 11 rain gauge stations over a 20-year period (2000–2020) on various temporal scales (daily, monthly, seasonal, and annual) using a pixel-to-point approach, employing different classification and regression metrics of machine learning. According to the findings, the GPM products showed high accuracy with a low margin of error in terms of bias, RMSE, and MAE. However, it was observed that ERA5 outperformed the GPM products in identifying spatial precipitation patterns and demonstrated a stronger correlation. The evaluation results also showed that the gridded precipitation products performed better during the summer months for seasonal assessment, with relatively lower accuracy and higher biases during rainy months. Furthermore, these gridded products showed excellent performance in capturing different precipitation intensities, with the highest accuracy observed for light rain. This is particularly important for arid and semi-arid regions where most precipitation falls under the low-intensity category. Although gridded precipitation estimates provide global coverage at high spatiotemporal resolutions, their accuracy is currently insufficient and would require improvement. To address this, we employed an artificial neural network (ANN) model for bias correction and enhancing raw precipitation estimates from the GPM-F product. The results indicated a slight increase in the correlation coefficient and a significant reduction in biases, RMSE, and MAE. Consequently, this research currently supports the applicability of GPM-F data in North Western Morocco

Application of Analytical Hierarchy Process and Geophysical Method for Groundwater Potential Mapping in the Tata Basin, Morocco

Ensuring water availability for agriculture and drinking water supply in semi-arid mountainous regions requires control of factors influencing groundwater availability. In most cases, the population draws its water needs from the alluvial aquifers close to villages that are already limited and influenced by current climatic change. In addition, the establishment of deep wells in the hard rock aquifers depletes the aquifer. Hence, understanding the factors influencing water availability is an urgent requirement. The use of geographic information system (GIS), and remote sensing (RS), together with decision-making methods like analytical hierarchy process (AHP) will be of good aid in this regard. In the Tata basin, located in SE Morocco, ten factors were used to explain the groundwater potentiality map (GWPM). Five categories of potential zones were determined: very low (8.67%), low (17.74%), moderate (46.77%), high (19.95%), and very high (6.87%). The efficiency of the AHP model is validated using the ROC curve (receiver operating characteristics) which revealed a good correlation between the high potential groundwater zones and the spatial distribution of high flow wells. Geophysical prospecting, using electrical resistivity profiles, has made it possible to propose new well sites. It corresponds to conductive resistivity zones that coincide with the intersection of hydrogeological lineaments