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1.
Al Hoceima is one of the most seismic active regions in north of Morocco. It is demonstrated by the large seismic episodes reported in seismic catalogs and research studies. However, seismic risk is relatively high due to vulnerable buildings that are either old or don’t respect seismic standards. Our aim is to present a study about seismic risk and seismic scenarios for the city of Al Hoceima. The seismic vulnerability of the existing residential buildings was evaluated using the vulnerability index method (Risk-UE). It was chosen to be adapted and applied to the Moroccan constructions for its practicality and simple methodology. A visual inspection of 1102 buildings was carried out to assess the vulnerability factors. As for seismic hazard, it was evaluated in terms of macroseismic intensity for two scenarios (a deterministic and probabilistic scenario). The maps of seismic risk are represented by direct damage on buildings, damage to population and economic cost. According to the results, the main vulnerability index of the city is equal to 0.49 and the seismic risk is estimated as Slight (main damage grade equal to 0.9 for the deterministic scenario and 0.7 for the probabilistic scenario). However, Moderate to heavy damage is expected in areas located in the newer extensions, in both the east and west of the city. Important economic losses and damage to the population are expected in these areas as well. The maps elaborated can be a potential guide to the decision making in the field of seismic risk prevention and mitigation strategies in Al Hoceima. 相似文献
2.
Dissolution rates of sediments obtained from the Oued Cherf reservoir were measured in closed-system batch reactors at 25 °C in fluids sampled concurrently from the same locations as the sediments. The BET surface areas of the sediments ranged from 16 to 45 m2/g and consisted primarily of quartz, calcite, and clay minerals. After a brief initial period, release rates of Si, Mg, Ca, Cl, SO4, and NO3 from these sediments are approximately linear with time over the course of the experiments, which lasted from 3 to 5 months. BET surface area normalized Si release rates ranged from 10–17.4 to 10–18.4 mol/cm2/s. These release rates match closely Si release rates from quartz and clay minerals determined from laboratory dissolution rates reported in the literature. This coherence suggests that laboratory measured silicate dissolution rates can be used with confidence to predict the dissolution behavior of sediments in natural surface waters. 相似文献
3.
Water Resources - Annaba gulf is a coastal area (southwestern Mediterranean Sea) that receives large diffuse inputs from Fertial plant, Seybouse wadi and Boujemaâ wadi, which are influenced by... 相似文献
4.
Rachid Benkadja Ali Hattab Nora Mahdaoui Cherif Zehar 《Arabian Journal of Geosciences》2013,6(10):3959-3968
Soil losses and siltation of the hydrological system (watershed–dam) of K’sob were obtained using direct and indirect methods. The Wadi K’sob watershed of 1,484 km2, average slope of 0.14, and average elevation of 1,060 m is located in a semiarid climate. The average annual rainfall is 341 mm and the mean annual water discharge is 0.89 m3/s. Data from the Medjez gauging station located 6 km upstream of the dam, are the daily liquid flow and instantaneous concentrations of suspended sediments. Over a time period from 1973 to 2010, the relationship between water and sediment discharges is quantified by the equation: Q s?=?5.6 Q 1.31. Thus, in view of the availability data on a daily scale, the assessment of soil erodibility of the K’sob watershed was used to estimate specific soil losses of 203 t?km?2?year?1or 301,000 t eroded annually from the K’sob basin. The bathymetric measurements of the sediment volumes deposited in the K’sob dam, has quantified the annual siltation of 0.8 hm3, corresponding to an average erodibility of the K’sob watershed of 809 t?km?2?year?1. However, when adding the volume of sediment removed by the dredging operation and de-silting by the valves during heavy floods, the value of soil losses is 2,780 t?km?2?year?1. The indirect assessment of soil erodibility of the basin was obtained by applying two models: the quantitative geomorphological analysis (QGA) and PISA model (prediction of silting in the artificial reservoirs, in Italian: Previsioni dell’Interimento nei Serbatoi Artificiali) using physical and climatic factors in the watershed. The obtained results by QGA method underestimate specific soil losses of 524 t?km?2?year?1. The PISA model gives a value of 2,915 t?km?2?year?1, which is close to the value obtained by bathymetric measurements. This study concludes that PISA model is most suitable to estimate soil loss and siltation of the K’sob hydrological system. 相似文献
5.
Delineation of groundwater potential zones in Wadi Saida Watershed of NW-Algeria using remote sensing,geographic information system-based AHP techniques and geostatistical analysis 
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下载免费PDF全文 Sustainable management of groundwater resources has now become an obligation,especially in arid and semi-arid regions given the socio-economic importance of this resource.The optimization in zoning for groundwater exploitation helps in planning and managing groundwater supply works such as boreholes and wells in the catchment.The objective of this study is to use remote sensing and GIS-based Analytical Hierarchy Process(AHP)techniques to evaluate the groundwater potential of Wadi Saida Watershed.Spatial analysis such as geostatistics was also used to validate results and ensure more accuracy.Through the GIS tools and remote sensing technique,earth observation data were converted into thematic layers such as lineament density,geology,drainage density,slope,land use and rainfall,which were combined to delineate groundwater potential zones.Based on their respective impact on groundwater potential,the AHP approach was adopted to assign weights on multi-influencing factors.These results will enable decision-makers to optimize hydrogeological exploration in large-scale catchment areas and map areas.According to the results,the southern part of the Wadi Saida Watershed is characterized as a higher groundwater potential area,where 32%of the total surface area falls in the excellent and good class of groundwater potential.The validation process revealed a 71%agreement between the estimated and actual yield of the existing boreholes in the study area. 相似文献
6.
Miloud Sallaye Khoudir Mezouar Yousra Salem Cherif Abd El Alim Dahmani 《Arabian Journal of Geosciences》2018,11(19):602
The morphological evolution of shallows seabed has undergone great changes over the past 95 years. These changes have not only led to the decreases of water volume but also to the spatial variability of sediments. However, the distribution and the movement of marine sediments from underwater beaches are very complex due to the combination of several factors such as hydrodynamic factors (e.g., tidal currents ±?34 cm, swells and currents driven by the prevailing northeast wind), and entropic factors (e.g., soil occupation and protective installation of structures as breakwater, groynes, retaining wall). This situation can disrupt the sedimentary regime in the Boumerdes area. In order to better understand the hydrodynamic processes, the recognition of sedimentary processes, the modalities, and erosion mechanisms of this zone are necessary. Thus, the study of long-term underwater morphological evolution by comparing between the bathymetric surveys of different years, between 1922 and 2017, is required to study the feasibility of coastal engineering projects. The seabed bathymetric evolution of this coastal fringe from erosion point of view was appreciated. It is based on a geographic information system (GIS), which allows to carry out a digital depth model interpolated by kriging method. 相似文献
7.
Mebarka Takorabt Ahmed Cherif Toubal Hamid Haddoum Siham Zerrouk 《Arabian Journal of Geosciences》2018,11(4):76
This paper attempts an overview of the application of remote sensing to groundwater studies. Its objective is to define the role of the geological features in the underground hydrodynamic in the aquifer system of the Chott El Gharbi Basin (Algerian western high plains) and identify a link between the fracturing and the meteoric water supply of this deep aquifer. The methodology followed consists to study the fracturing map of studied area which is obtained after Landsat 7 ETM+ processing images. It is based on structural lineaments mapping. The obtained map has been validated by geophysical results and geological map. Statistical analysis of the lineaments network shows the presence of about 537 lineaments divided into four families oriented according to the following directions NE-SW, NW-SE, N-S, and E-W. The lineament analysis of the studied basin provides important information on subsurface fractures that may control the circulation and storage of groundwater. These fractures have an undeniable hydrogeological interest because of their size, a priori favorable for the aquifers recharge in the region. The probable link between the Chott El Gharbi implementation and the presence of mega fractures which some of them correspond actually to Wadis is confirmed. The correlation between the productivity of high debit drillings and the closest lineament confirms that these lineaments are surface traces of regional discontinuities and act as main groundwater flow paths. 相似文献
8.
Mechanical behaviour study of soil polluted by crude oil: case of Sidi El Itayem oilfield,Sfax, Tunisia 总被引：1，自引：1，他引：0
The pollution of soils by xenobiotic organic substances such as crude oil constitutes major environmental risks, which are
still badly evaluated. The environmental risks are caused by the direct contamination of the surrounding areas or by an effect
on the living organisms in the soils, thus acting directly on man via the food chains. For these reasons, it is essential
to study the effects of these pollutants in the soil. The general objective of the work was to better characterize the mechanical
behaviour of sites polluted by crude oil in the short and medium terms (case of oilfield of Sidi El Itayem, Sfax, Tunisia
under the supervision of the Franco-Tunisian Oil Company). The process consists of determining and comparing the physicochemical,
mechanical and geotechnical characteristics of virgin soil and soil artificially polluted by crude oil according to various
pollution rates reaching 15% of the weight of virgin soil. This process made it possible to generate scientific knowledge
and data, which could allow the prediction of the effects of the latter in interaction with the soil. 相似文献
9.
Mahmoudi Youcef Cherif Taiba Abdellah Hazout Leila Belkhatir Mostefa 《Acta Geotechnica》2022,17(8):3269-3292
The published literature has revealed conflicting results regarding the effect of low plastic fines fraction (Ip?≤?5.0%) on the mechanical behavior of sandy soils. For this reason, the use of different sample initial structures as (initial relative density approach, global void ratio index approach, etc.) could explain these different mechanical responses of granular materials. Thus, it is necessary to evaluate the quantitative aspect of the low plastic fines effects on the undrained monotonic response of sand-silt mixtures using the global void ratio approach. To achieve this goal, an experimental testing program through controlled monotonic triaxial tests was carried out on reconstituted saturated Chlef sand containing from 0 to 50% silt with an interval of 10% at three global void ratios (e?=?0.64, 0.66 and 0.68) and subjected to constant confining pressure (σ'3?=?100 kPa). The different samples were reconstituted using two different preparation techniques: DFP and MT. The obtained results show that the low plastic fines content appears as a very relevant parameter in the characterization of the mechanical response of sand-silt mixture samples reconstituted at constant global void ratios, where the steady state shear strength and instability shear strength decreased with the increase in low plastic fines content up to the limiting fines contents (Fc?=?40% and Fc?=?10%) considering both studied initial structures (Dry funnel pluviation and Moist tamping), respectively. Beyond these thresholds fines contents, a reverse trend was observed for all parameters under study. Moreover, the test results indicate that the brittleness index, flow potential (Vf), friction index, equivalent void ratio (e*) and equivalent relative density (Dr*) could be considered as reliable parameters in the prediction of the mechanical behavior of the silty sand soils under study.
相似文献10.
Kara L. English Jonathan Redfern Giovanni Bertotti Joseph M. English Rachida Yahia Cherif 《Basin Research》2017,29(3):377-393
Zones of anomalously high topography within continental interiors, distant from active plate boundaries, are interpreted as being either dynamically supported by viscous flow in the underlying mantle or influenced by plate tectonics. Constraining the models of their genesis requires accurate data on the timing and dimensions of such features. New apatite fission‐track and thermal maturity data from the Illizi Basin in Algeria quantify the magnitude and timing of kilometre–scale uplift and exhumation of the northern flank of the Hoggar swell in North Africa. The findings of this study, integrated with previously published thermochronological data, confirm that long‐wavelength regional uplift occurred during the Cenozoic extending over a distance in excess of 1500 km from north to south. The uplift, centred on the Hoggar Massif, significantly impacted the flanking Illizi and Tim Mersoï basins. The combination of thermal history modelling and regional stratigraphic observations indicates that the onset of exhumation of the Illizi Basin likely occurred during the Eocene, broadly coincident with magmatism on the Hoggar Massif to the south and the onset of tectonic shortening in the Atlasic belt to the north. 相似文献