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Khomsi K.,Direction de la Meteorologie Nationale | Mahe G.,IRD Montpellier | Tramblay Y.,IRD Montpellier | Sinan M.,Ecole Hassania des Travaux Publics | Snoussi M.,Mohammed V University
Natural Hazards and Earth System Sciences | Year: 2016

In Morocco, socio-economic activities are highly vulnerable to extreme weather events. This study investigates trends in mean and extreme rainfall, run-off and temperature, as well as their relationship with large-scale atmospheric circulation. It focuses on two Moroccan watersheds: the subhumid climate region of Bouregreg in the north and the semi-arid region of Tensift in the south, using data from 1977 to 2003. The study is based on a set of daily temperature, precipitation and run-off time series retrieved from weather stations in the two regions. Results do not show a homogeneous behaviour in the two catchments; the influence of the large-scale atmospheric circulation is different and a clear spatial dependence of the trend analysis linked to the distance from the coast and the mountains can be observed. Overall, temperature trends are mostly positive in the studied area, while weak statistically significant trends can be identified in seasonal rainfall, extreme rainfall events, average run-off and extreme run-off events. Source

Mahe G.,Hydrosciences | Aderghal M.,University Mohammed Premier | Alkarkouri J.,Universite Ibn Tofail | Benabdelfadel H.,Planification de lEau | And 30 more authors.
IAHS-AISH Proceedings and Reports | Year: 2013

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. Copyright © 2013 IAHS Press. Source

Demers I.,University of Quebec | Bussiere B.,University of Quebec | Aachib M.,Ecole Hassania des Travaux Publics | Aubertin M.,Ecole Polytechnique de Montreal
Water, Air, and Soil Pollution | Year: 2011

Instrumented column tests are often used to assess the effectiveness of methods to prevent acid mine drainage (AMD). These tests are seldom duplicated, and this lack of duplicate can cast some doubt about their repeatability and reliability. This paper provides an analysis of column test studies (with duplicates) performed with a commonly used methodology. The paper presents the analysis of two multi-layer covers with capillary barrier effects in which the water retention layer was made of a non-plastic silt and of two cover scenarios involving a single-layer low sulphide cover. The first study compared the cover performance to limit AMD when different cover materials are used, while the second study compared the thickness of covers on cover performance. Statistical comparison between duplicates was made using available geochemical data, hydro-geotechnical data, and gas concentrations. Student's t-test statistical tools and analysis of variances were used to determine the repeatability of the data. The results indicate that a good reproducibility of the column tests can be achieved with a good set-up methodology and rigorous control of the boundary conditions. © 2010 Springer Science+Business Media B.V. Source

Grandcoin J.,Ecole Centrale Marseille | Boukamel A.,Ecole Hassania des Travaux Publics | Lejeunes S.,Ecole Centrale Marseille
International Journal of Solids and Structures | Year: 2014

This paper presents a continuum damage model based on two mechanisms: decohesion between fillers and matrix at a micro-scale followed by a crack nucleation at a macro-scale. That scenario was developed considering SEM observations and an original experimental procedure based on simple shear and tension specimens. Damage accumulation is related to fatigue life using the continuum damage mechanics (CDM). The material behavior is investigated using the statistical framework introduced by Martinez et al. (2011). A Finite Element implementation is proposed and some numerical examples are provided. © 2013 Elsevier Ltd. All rights reserved. Source

Tabaa M.,CNRS System Conception, Modelisation, and Optimsation Laboratory | Diou C.,CNRS System Conception, Modelisation, and Optimsation Laboratory | Saadane R.,Ecole Hassania des Travaux Publics | Dandache A.,CNRS System Conception, Modelisation, and Optimsation Laboratory
Procedia Computer Science | Year: 2014

This paper presents a technique for identifying between both Line-Of-Sight (LOS) and Non-Line-Of-Sight (NLOS) propagation schemes for UWB on-body context. The wireless communications for body area networks have a great attention in the last years especially after the IEEE 802.15.6 standard. We focus in the first to extract only the pertinent information using Stable Distribution compared with statistical techniques, and secondly to classify it using Support Vector Machine (SVM) with as main goal to identify the two LOS and NLOS phenomena. We propose a technique to make the classification easy between LOS and NLOS contexts for UWB on-body communications. All simulations were applied to UWB measurements collected in. © 2014 Published by Elsevier B.V. Source

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