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Located in arid regions, the foggara in Algeria, the Qanat in Iran, Khettara in Morocco and Falj in Oman, are a system used for the acquisition and distribution of water, based on horizontal drainage galleries. However, although there are similarities in their collection system (galleries and shafts), these traditional techniques show differences in their water source and in the technique of water sharing. Through this study, based on prospecting trips in five oases of the Algerian Sahara and investigations at the oases, we could identify seven types of foggara, namely: those that receive water from the water table at the foot of a mountain range; those that drain the waters of the intermittent streams; which receive waters from the “Continental Intercalaire” aquifer; which receive water from a spring; which receive the waters from the Occidental Great Erg aquifer; which capture drainage and infiltration; and finally those that capture only flood waters (foggara of Mzab).

Keywords: Sahara, Algérie, Foggara, Nappe, Source, Albien, Oued, Sahara, Algeria, foggara, qanat, groundwater, spring, intermittent stream

Most of the works achieved so far in semi-arid lakes have been focused especially on the dynamics, structure and metabolic of phytoplankton. However, this issue has not been addressed in term of metabolic microphytobenthic cells activity. With an aim increasing the relative scientific knowledge relating to the functioning of lacustrian ecosystems in the Maghreb for which the data are still very fragmentary, special attention has been granted to the study of the microphytobenthos metabolism, by means of determining essential cellular constituents (carbohydrates, proteins and lipids) of the reservoir Allal El Fassi.The Allal El Fassi reservoir is about 47 km of Fez. It was built in 1992, and is 7 km long, 0.7 km wide and 34 m maximum depth. The reservoir is classed as mesotrophic and used for irrigation, recreation and to supply drinking water.The study was conducted between August 1996 and July 1997. Samples were taken vertically from the deepest point of the reservoir by means of a Van-Dorn sampler from seven depths: Near the surface, - 2 m, - 5 m, - 10 m, - 15 m, - 20 m and close to the bottom. The samples were analysed for physical, chemical and metabolism of Diatom. Analysis of Nitrogen and phosphate was done following Golterman method and oxygen dissolved by the Winkler method.Given the advantage that presents the artificial substrata (polyethylene leaves) for sample of periphyton, we have opted for the utilization of these substrata similar to these already used by WATANABE et al. (1988). These substrata are submerged during four weeks at different depths.The evaluation of the microphytobenthic biomass has been carried out according to the method of LOHMAN (1908) after enumerations to the microscope Olympus following the technique of LECLERCQ (1984).The dosage of the carbohydrates has been undertaken according to the method of MOAL et al. (1985), while concentrations of proteins have been determined according to the method of LOWRY (1951) and lipids have been extracted according to the method chloroform/methanol.The results show that microphytobenthic biomass presents important fluctuations since extreme values are respectively 0.25·104 µg·cm-2 and 14.95·104 µg·cm-z.Carbohydrates and lipids concentrations (mean=4.52 µg·cm-z and 2.27 µg·cm-z, respectively) are clearly less high than those of proteins (mean=81.84 µg·cm-2). This result indicates that the metabolism of the microphytobenthos of the Allal El Fassi reservoir is oriented towards the preferential protein synthesis. The vertical distribution of proteins, carbohydrates and lipids concentrations shows a well marked stratification, maximal concentrations generally recorded between 0 and 5 m. These high concentrations are attributed to the development of Niztchia, Navicula, Cymbella, Cyclotella, Melosira and Cocconeis.Proteins and carbohydrates concentrations were significantly correlated (r=0.84, p=0.01 at 0m and r=0.52, p=0.10 at 5 m). On the opposite, concentrations of lipids have no correlation neither with those of proteins, nor with those of the carbohydrates.The correlation between the lipids concentrations and the microphytobenthic biomass, is highly significant (r=0.48, p=0.10). This correlation results notably into the fact that lipids visualise well the evolution of the microphytobenthic biomass. However, no significant correlation was found between proteins, carbohydrates concentrations and biomass microphytobenthic.Many works prove the influences of some environmental factors namely light intensity and the temperature on the biochemical composition of the microphytobenthic. In this way, we observe that in period of high temperature, the synthesis of lipids is important. The positive correlation between temperature and lipids (r=0.48, p=0.10) support the observed increase in the concentrations of this variable with increasing temperature. Nevertheless, no significant correlation was found between proteins and carbohydrates concentrations and temperature, which suggests that the synthesis of these components is made independently from this factor. Oxygen dissolved and nitrogen intervene equally in the synthesis of lipids.

Keywords: Réservoir, microphytobenthos, lipides, protéines, glucides, Reservoir, microphytobenthic, carbohydrates, proteins, lipids

This work deals with the overall process and the positive and negativeeffects of the breakdown of leaves, which is a major feature of thefunctioning of heterotrophic aquatic systems. The aim of the study wasto evaluate the relationship between the stream and the adjacentterrestrial ecosystem, since is at the land/water interface thatimportant features of ecosystem functioning can be found. We have usedthe technique of mesh bags with 0.5 cm openings that allow for easyaccess by a large proportion of the aquatic invertebrates thatcontribute to the degradation of leaves in water. We have alsointroduced two or three stones in order to anchor the mesh bags on thestreambed. Regarding the degradation of the leaves, we found that theoleander leaves decompose and lose their weight faster than theeucalyptus leaves, this loss being very rapid, reaching a value of 70%of the initial weight after 30 days. The initial weight loss could berelated to leaf leaching, which depends on the texture and structure ofthe leaves and the action of invertebrates, especially of molluscs(macerators) and Diptera (filterers) that contribute in large measureto the degradation of the leaves. This period of weight loss is quiteshort for oleander leaves (15 days), while it is relatively long forthose of eucalyptus (30 days), the colonization of which byinvertebrates, both in number and biomass, remains lower than that ofoleander bay leaves.

Keywords: Décomposition, feuilles, milieux aquatiques, laurier rose, eucalyptus, lessivage, Decomposition, leaves, aquatic, oleander, eucalyptus, leaching

The composition of the diet of the barbel (Luciobarbus callensis) was studied in the K'sob reservoir near the town of M'Sila (Algeria). The capture of the barbels was carried out between September 2010 and August 2011.The diet was studied from 379 specimens collected by trammel net. During the study period, it was noted that the food spectrum essentially consisted of Chironomids, Ephemeroptera and Copepods, which are abundant in the environment. The barbel of the K'sob reservoir has a seasonal food pattern influenced by climatic and ecological conditions and by its reproductive cycle. The diet of L. callensis in the study area is omnivorous, with a zoo-benthophage tendency.

Keywords: régime alimentaire, barbeau, saison, barrage, Algérie, diet, barbel, season, reservoir, Algeria

AbstractMaghrebin writers and their work in Quebec reveal that they are actors in and mechanisms for the transmission of their history and immigration experiences. This article presents two writers—Majid Blal and Wahmed Ben Younes. Their life and work serve to reveal how they are witnesses to history and they make history, and that they are thereby mediators. In addition their action of writing and the publication of their works allows for the integration of personal change following from immigration as well as contributing to a feeling of attachment to the host society.

SummaryThe main point raised by this study concerns the issue of relevance and reliability of methods used to analyze needs of higher education teachers in terms of pedagogical training. A comparative study between two approaches of needs analysis according to, on the one hand, the definition of the concept of need (drive or gap) and, on the other, the context in which the questionnaire is administered (at distance or in presence) – shows a significant difference in needs prioritization and that this difference depends not only on the definition of the concept of need, but also on the level of explicitness of the questionnaire.

Keywords: analyse des besoins, méthode du drive, méthode de l'écart, enseignants du supérieur, formation à la pédagogie universitaire, needs analysis, drive method, gap method, higher education teachers, university pedagogy training, análisis de las necesidades, método del drive, método de desviación, profesores de enseñanza superior, formación en pedagogía universitaria

This paper looks at the effect of dam impoundments on the flood synchronicity of the Moulouya River (Morocco) and its consequences on the morphological adjustments of its ephemeral tributaries. The comparative analysis of monthly discharges measured upstream and downstream of the dams shows a diminution of 52% of mean discharges and a diminution of 33% of annual maximum discharges. The frequencies of discharges reaching 50, 75 and 100 m³•s-1 values are respectively reduced by 55, 47 and 22%. Monthly variations are levelled and this leads to a homogeneous discharge regime (coefficient of immoderation for median values decreases from 8.99 to 1.23). Flood coincidence in time is assessed and shows that downstream discharges are independent of upstream discharges. The description of longitudinal profiles of tributaries downstream of the dams reveals morphological singularities such as convex profiles, perched accumulation forms on the alluvial plain and knickpoints. Three models of morphological adjustments (convex, mixed and by flooding) based on the synchronicity of floods between the main channel and its tributaries are proposed to explain these morphological observations. The convex adjustment model occurs when floods are synchronous and explains the observation of convex profiles. The mixed adjustment model occurs when tributaries are flooded and the main channel remains to its base level and explains morphological forms such as scouring of tributaries or perched accumulation forms on the alluvial plain. Finally, the model of adjustment by flooding occurs when the main channel is activated and the tributaries remain inactive and explains knickpoints and the lack of integration observed at the mouths of the tributaries. Asynchronous flooding induced by dam impoundments is proposed as the main factor affecting tributary adjustments in semi-arid environments.

Keywords: Barrage, synchronisme, ajustement morphologique, impact hydrologique, tributaires, Maroc, Dam, tributary, synchronism, morphological adjustments, hydrologic impact, Morocco

In the Deroua fish farm (Béni-Mellal, Morocco), a series of ponds was lined with polyethylene to prevent water seepage (lined ponds, C). Another series of ponds was not lined (unlined ponds, A). The lined ponds do not need much fertiliser to enhance phytoplankton growth. They receive a small quantity of urea and triple super phosphate and accumulate high levels of organic matter in their sediments. The unlined ponds receive a large quantity of fertilisers. In the ponds, an important increase in phytoplankton growth occurred particularly after fertilisation with triple super phosphate. The phosphate (P) released from the sediment is the essential source of P for phytoplankton when the ponds are not fertilised.Sediment samples used in this study were collected in June 1999 from the A1 and C1 ponds of the Deroua fish farm. The bottom sediments were collected with a core sampler to provide samples from the 0-5 cm layer. The samples were mixed and analysed for pH, total Kjeldahl nitrogen (NTK), nitrates (N-NO3-), ammonium (N-NH4+), total iron (tot-Fe) and P-fractionation in eight replicates, using the Golterman method (1996).In this work, experiments were conducted to evaluate the P released from sediments of lined and unlined ponds under controlled conditions. The samples included: untreated sediments, sediments treated with hydrogen peroxide (H2O2), and sediments treated with chloroform (CHCl3). H2O2 was used to destroy the organic matter of sediment. To inactivate bacteria, CHCl3 was added to the sediments. CHCl3 does not modify the mineral and organic structures of sediments but does reduce the bacterial biomass. Urea and triple super phosphate were added to Chinese carp rearing ponds at Deroua fisheries farm to stimulate algal growth. However, phosphate bound to the sediments was released into the water column during anaerobic conditions. The released phosphate from lined pond (C1) enhanced the algal production.We have tested the fertilisation capacity of A1 and C1 ponds as well as the effects of different factors such as dissolved oxygen, pH, nitrate, and organic matter (glucose) on the phosphate released from the sediments. The results show that under anoxic conditions, phosphate solubility increased in the interstitial water. The released phosphate (873 µg/l) comes from the mineral fraction, particularly from Fe(OOH)=P. The P released from the A1 untreated sediment under oxic and anoxic conditions was low in comparison to the P released from the C1 untreated sediment and did not exceed 9.1 µg.g-1 d.w. (Figure 1). The removal of organic matter with H2O2 had a positive effect on the P released from the C1 sediments only after the second day of incubation. The inactivation of bacteria with CHCl3 had an inhibitory effect on the P released from the C1 sediments under oxic and anoxic conditions; however for the A1 sediments, this inactivation of bacteria had no effect on the kinetics of P release. Phosphorus release from the C1 sediments was important under anoxic conditions; the P came from Fe(OOH)=P after the reduction of Fe(OOH).The addition of nitrates decreased the mobilisation of phosphate from the sediments. Acid conditions increased the dissolution of calcium-bound phosphate, while alkaline conditions increased the dissolution of iron-bound phosphate and its re-precipitation onto carbonate present in sediments. High concentrations of organic matter (glucose) increased oxygen demand and favoured the development of reducing conditions. The phosphate was released from Fe(OOH)=P.The conceptual model of P released in fish ponds shows that, in semiarid climates and in calcareous areas, the polyethylene lining of ponds prevents not only the seepage of water but also the percolation of nutrients. Consequently, the P was more available for algal uptake in the lined ponds. More phosphate will be released concomitant with the process of the ponds becoming anoxic, as nitrate concentrations and the pH of sediments decrease.

Keywords: Maroc, Deroua, orthophosphates, relargage, anaérobie, percolation, polyéthylène, Morocco, Deroua, orthophosphates, release, fertilisation, oxic, anoxic, lined pond, production, fish