排序方式： 共有49条查询结果，搜索用时 15 毫秒
31.
Abdelkader Benaïssa Zahia Benaïssa Tahar Aïfa Amar Boudella 《Swiss Journal of Geoscience》2009,102(2):297-306
To improve the signal to noise ratio of the vertical seismic profile recordings, we used a filtering method based on pattern
recognition. It consists in recognizing along the seismic trace, corresponding to the arrivals of various events, the shape
of the P wavelet considered as the training signal. This recognition is made of projections which retain only the signals
similar in shape to the P wavelet, the others being attenuated according to their degree of resemblance to the training wavelet.
The study undertaken on synthetic and real data shows that this method acts as an effective filter. However, it still depends
on a training signal that must be well defined and identifiable. 相似文献
32.
Assessment of water quality index for the groundwater in the upper Cheliff plain,Algeria 总被引：1，自引：0，他引：1
Abdelkader Bouderbala 《Journal of the Geological Society of India》2017,90(3):347-356
Assessment of groundwater suitability for drinking and agricultural purposes was carried out in the plain of upper Cheliff. The study area covers an area of 375 km2 and lies in a semiarid climate. Groundwater is the major source for domestic and agricultural activity in this area. Groundwater samples were collected from 19 wells during dry and wet periods in 2012, and they were analyzed for major cations and anions and compared with drinking and irrigation specification standards. The concentration of the majority of chemical constituents exceeds the standards of WHO as a result of various sources of pollution. It indicates the dominance of groundwater types: Ca-Mg-Cl, and Ca-Mg-HCO3. Suitability of groundwater for drinking was evaluated based on the water quality index; it shows more than 60% of samples have very poor quality for dry and wet periods, which means water is severely contaminated and unsuitable for drinking purpose. In terms of the irrigation usage, generally groundwater is suitable for both periods in the major part of the plain. The Mineralization processes in this area is determined by the lithology of the aquifer (exchange water-rock), by anthropogenic factors (discharges of urban sewage, use of fertilizers) and also by evaporation (semi-arid climate). 相似文献
33.
Gärtner Andreas Youbi Nasrrddine Villeneuve Michel Sagawe Anja Hofmann Mandy Mahmoudi Abdelkader Boumehdi Moulay Ahmed Linnemann Ulf 《International Journal of Earth Sciences》2017,106(8):2747-2769
International Journal of Earth Sciences - Detrital zircon provenance studies are an established tool to develop palaeogeographic models, mostly based on zircon of siliciclastic rocks and isotope... 相似文献
34.
Mortadha Ben Hassine Olfa Boussadia Ahmed Ben Abdelkader Ines Moula Mariem El Hafi Mohamed Braham 《Arabian Journal of Geosciences》2017,10(14):302
Olive trees are grown under high evaporative demand and less precipitations that are variable in time and space especially in semi-arid conditions. The objective of this work is to determine the most efficient water treatment applied in an olive field (Olea europaea L. cv Chemlali) from the 98th to the 294th Julian day, in Tunisian semi-arid conditions. The choice of this time frame was done to control the effect of irrigation on the trees behavior in the irrigation period of the year (from April to October) and determine the most sensitive phenological stages to irrigation. For this reasons, two water treatments were applied: T100% (irrigation at 100% of Available Water Content (AWC)) and T50% (irrigation at 50% AWC). The results show that, according to leaf water potential, carbon isotope discrimination, and olive production parameters, the T50% AWC water treatment is the most efficient. The leaf water potential of the two water treatments applied has not exceeded ?2.5 MPa during the whole experiment which indicates that the trees of the two water treatments were not stressed. The T50% AWC shows a water use efficiency of 5.18 g/l compared to 2.93 g/l for T100% water treatment. This result demonstrate that Chemlali cultivar valorizes better low quantities of water rather than high quantities, so saving 50% of water resources applied will ensure the sustainability of water resources and stability of olive production. 相似文献
35.
Clay and Marl Formation Susceptibility in Mila Province,Algeria 总被引：2，自引：2，他引：0
Djamel Athmania Abdelkader Benaissa Achour Hammadi Mounir Bouassida 《Geotechnical and Geological Engineering》2010,28(6):805-813
In Mila Province, Algeria (a.k.a Mila Wilaya), sensitive clays presenting shrinkage-swelling phenomena are widespread, covering
large areas. Due to this, constructions and infrastructures sustainability built on such soils is questionable. Such clays
sensitivity is amplified by seasonal rainfall deficits which reaches extreme magnitudes. In order to develop disasters’ prevention
measures, we present in this work, areas mapping susceptible to shrinkage-swelling phenomenon by adopting a French method
developed by B R G M. This method takes into account three measurable characteristics: i.e. lithological, mineralogical and
geotechnical, of clayey formations identified in the studied sector. Based on these characteristics, three scores are attributed
for each formation. Then, the susceptibility index is the obtained score average for each clayey formation. The susceptibility
map is established on this index basis with three classes: low, medium, high. 相似文献
36.
Evaluation and numerical modeling of seawater intrusion in the Gaza aquifer (Palestine) 总被引：3，自引：1，他引：3
A numerical assessment of seawater intrusion in Gaza, Palestine, has been achieved applying a 3-D variable density groundwater flow model. A two-stage finite difference simulation algorithm was used in steady state and transient models. SEAWAT computer code was used for simulating the spatial and temporal evolution of hydraulic heads and solute concentrations of groundwater. A regular finite difference grid with a 400 m2 cell in the horizontal plane, in addition to a 12-layer model were chosen. The model has been calibrated under steady state and transient conditions. Simulation results indicate that the proposed schemes successfully simulate the intrusion mechanism. Two pumpage schemes were designed to use the calibrated model for prediction of future changes in water levels and solute concentrations in the groundwater for a planning period of 17 years. The results show that seawater intrusion would worsen in the aquifer if the current rates of groundwater pumpage continue. The alternative, to eliminate pumpage in the intruded area, to moderate pumpage rates from water supply wells far from the seashore and to increase the aquifer replenishment by encouraging the implementation of suitable solutions like artificial recharge, may limit significantly seawater intrusion and reduce the current rate of decline of the water levels. 相似文献
37.
Ridha Abdessalem Gharbi Lassaâd Chihi Mongi Hammami Abdelkader Soumaya Ali Kadri 《Comptes Rendus Geoscience》2005,337(14):1293-1300
The geodynamic evolution of the diapir of Zag Et Tir is the result of the coexistence of the diapiric and tectonic activity from the Upper Cretaceous until the Quaternary. The interference of the tectonic and diapiric phenomena is at the origin of the basin individualization with differential sedimentation during the Miocene. This explains the current distribution of the Neogene deposits on both sides of Zag Et Tir Triassic structure. The submeridian faults that subdivide our sector played a significant role during the Atlasic compression, inducing an unequal distribution of the folds on both sides of these accidents, as well in kind as in number, showing the anteriority of the faults compared to the folds. To cite this article: R.A. Gharbi et al., C. R. Geoscience 337 (2005). 相似文献
38.
Abdennour Mohamed Amine Douaoui Abdelkader Barrena Jesús Pulido Manuel Bradaï Abdelhamid Bennacer Amel Piccini Chiara Alfonso-Torreño Alberto 《中国地球化学学报》2021,40(2):234-250
Acta Geochimica - The agriculture in Biskra, southeastern Algeria, is based on traditional practices and characterized by small irrigated fields. In the last decades, the increasing demand in water... 相似文献
39.
The demand on green and clean energy is increasing all over the world. This urge us to try to reduce the obstacles in this field. One of the main obstacles is the high cost of offshore foundation system of wind turbines. A novel offshore hybrid foundation system is proposed for large offshore wind turbines to try to reduce the construction cost. This new system consists of circular precast concrete plate connected on site (i.e. offshore) to a steel monopole that is smaller than the usual pile size used. Parametric study for different foundations systems including monopiles had been done. The displacements at different locations of the foundation and the rotation at the pile head were analyzed and evaluated using a 3D nonlinear finite element model under field-like loading conditions considering different foundation configurations. This work paves the way for the development of design guidelines for this novel foundation system in offshore wind turbine applications. 相似文献
40.
Mouez Gouasmia Houyem Khorchani Abdelkader Mhamdi Ferid Dhahri Mohamed Soussi 《Arabian Journal of Geosciences》2018,11(24):786
An integrated hydrogeological investigation involving geological surface data, well data (lithostratigraphical and piezometric data) and the vertical electrical sounding (VES) method was carried out in Tataouine area, Southern Tunisia to characterize the hydrogeology and the geochemistry of the Krachoua Formation aquifer. The electrical data were used to differentiate lithostratigraphic units and characterize their hydrogeological potentialities. Major elements contents within groundwater samples were assessed and some plots and diagrams have been established in order to investigate the hydrochemical properties of this aquifer and the origin of its mineralization. The Krachoua aquifer exhibits a general drawdown of the piezometric level from 2004 to 2015 reflecting a dramatic decrease in groundwater resources due to increased groundwater abstraction during the last decades. Flow directions shows that the recharge of this aquifer considered as a free aquifer is directly ensured by rainfalls over the outcropping fractured limestones. The geometry of the Krachoua Formation aquifer is tectonically controlled and structured in horst and graben features that impacted greatly the hydrogeology and the hydrodynamics of the area. Subsequent thickness and facies variations within this aquifer influenced the reservoir quality and the groundwater flows. The increased values of salinity to the northwest of the study area seems to be mainly related to the dissolution of the Upper Liassic gypsum of Mestaoua Formation which outcrops widely and can be dissolute easily by meteoric water and contaminate the Krachoua aquifer. This fact is also supported by the sulfated and calci-magnesian chloride facies of this aquifer related to the dissolution of evaporitic rocks (gypsum, anhydrite, and halite). However low salinity values are recorded within the zone where these evaporitic rocks are relatively deep. 相似文献