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La ville de Tindouf est caractérisée par la fréquence des zones inondables qui affectent dangereusement de nombreux quartiers à forte densité de population. Ces sites affectés par d’importantes crues lors d’orages et affichent une grande vulnérabilité pour une population de 75 000 habitants, mais aussi pas moins de 15 000 constructions menacées de ruines : par l’ampleur des dommages spectaculaires aux constructions. La ville de Tindouf offre toutes les conditions de potentiel élevé de dégradation de l’habitat en Algérie. Les inondations ont pour origine des événements météorologiques et/ou hydrologiques de nature stochastique, sont très difficiles à prévoir quant à leur période de retour et à leur intensité. Une démarche méthodologique sur les anciennes agglomérations regroupant les quartiers [Remadine – Moussani - Guessabi] permettant ainsi de délimiter les zones vulnérables et de proposer des aménagements urbains pour leurs protections. Les résultats obtenus montrent la distribution spatiale de la vulnérabilité des quartiers historiques et proposent une approche de conservation pour le développement durable. The city of Tindouf is characterized by the frequency of flood zones which dangerously affect many densely populated neighbourhoods. These sites affected by major floods during thunderstorms and display great vulnerability for a population of 75,000 inhabitants, but also no less than 15,000 constructions threatened with ruins: by the extent of the spectacular damage to constructions. The city of Tindouf offers all the conditions of high potential for habitat degradation in Algeria. Floods originate from meteorological and/or hydrological events of a stochastic nature are very difficult to predict as to their return period and their intensity. A methodological approach on the old agglomerations grouping the districts [Remadine - Moussani - Guessabi] thus making it possible to delimit the vulnerable zones and to propose urban developments for their protections. The results obtained show the spatial distribution of the vulnerability of historic districts and propose a conservation approach for sustainable development.

This contribution represents a critical view of the advantages and limits of the set of mathematical models of the physical phenomena of turbulence. Turbulence models can be grouped into two categories, depending on how turbulent quantities are calculated: direct numerical simulations (DNS) and RANS (Reynolds Averaged Navier-Stokes Equations) models. The disadvantage of these models is that they require enormous computing power, inaccessible, especially for large and complicated geometries. For this reason, hybrid models (combinations between DNS and RANS methods) have been developed, for example, the LES (“Large Eddy Simulation”) or DES (“Detached Eddy Simulation”) models. They represent a compromise - are less precise than DNS, but more precise than RANS models. The results presented in this contribution will allow and facilitate future research in the field the choice of the model approach necessary for the case studies whatever their difficulty factor.

The hydrogeological environment of the Saharan North East region of Tindouf is of utmost interest, particularly in agriculture. In fact, exploitation and exploration processes must be analysed to ensure sufficient water production. This study demonstrates the value of spatial processing and exploitation of geoelectric and geological data in the study area and facilitates interpretation. The results of the electrical survey and the spatial analysis of the data allowed us to design a complete model that met the needs of hydrogeology. The applied methodology consists in breaking down our subject into three (3) classes of entities: geomatics, geophysics and hydrogeology. Synthetic mapping based on continuity is the result of studying two sites (Hassi Naga and Hassi Khebi) for geological analysis. Knowing that the electrical resistivity is between 0 and 3000 Ohm-meter, we were able to construct thematic maps showing the spatial distribution of the facies and the probable positions of the boreholes. The study provided with a geo-spatial model highlighting the impact of measurements in hydrogeology of the area considered that was called SIHE (Information System for Environmental Hydrogeology).

In the present study, simulations were carried out to determine the infiltration of a pollutant landfill in a homogeneous and isotropic slick. The system of basic equations, which govern the principle of conservation of the momentum coupled with Darcy's law, was developed to resolve the displacement of the pollutant in the water table studied as a function of time.The fields and profiles of the velocity and concentration were presented, the influence of the porosity and the permeability of the medium was taken into account to obtain the rate (%) of the water pollution concentration of the water table and their infiltration with respect to depth. The simulation results obtained show that for a porosity of 20% at the same time with infiltration rates of 1x10-5, 2x10-5 and 3x10-5 successively the concentration of the pollution compared to a depth of 3 (m) is equal to the following values: 20%, 45%, and 70%.

In this work, we propose a model of Geomatics in the Hassi Naga region, which is located in the Hamada of Tindouf, southwestern Algeria, about 70 km to the northwest of the region. This approach is based on prospecting and thematic analysis of the distribution of Geoelectrical measurements in order to better estimate and manage the Hydrogeology of this region of the Tindouf basin. The results of the geophysical survey allow us to design a complete model that meets the needs of Hydrogeology, whose methodology we have applied consists of decomposing our subject into three classes of entities: Geomatic, geophysical and hydrogeological, discovering the relational links, doing the thematic analysis and ending with results that help to solve the problem of water (Hydrogeology) of the area studied.

In the present research, simulations have been conducted to determine numerically the dynamic behaviour of the flow of underground water fed by a river. The basic equations governing the problem studied are those of Navier–Stokes equations of conservation of momentum (flows between pores), coupled by the Darcy–Forchheimer equations (flows within these pores). To understand the phenomena involved, we first study the impact of flow rate on the pressure and the filtration velocity in the underground medium, the second part is devoted to the calculation of the elevation effect of the river water on the flow behaviour in the saturated and unsaturated zone of the aquifer.

In this paper, the computational fluid dynamics technique (CFD) was used for air flow simulation in the solar chimney. The flow is assumed laminar, unsteady and incompressible. The air flow model consisted of a system of governing equations continuity, momentum, energy are solved for 2D Cartesian system uses the SIMPLE algorithm and the Power–Law differencing scheme. The influence of the variation depth of the solar chimney on the thermal efficiency of the system was studies. The principle of functioning of the system is visualized. The temperatures obtained on the level of the zone of occupation are adaptable to the interval of thermal comfort. The results of simulation are congruent with those of the literature.

In this work, two-dimensional and three-dimensional simulations on the flow in a room coupled with a facade of passive heating system type In-In (Trombe wall) were conducted numerically to determine the temperature and velocity fields in the influence of the variation of the modified Rayleigh number, which itself depends on the characteristics of the fluid and heat flow due to sunshine. The behavior of boundary layers in natural convection is analyzed along the Trombe wall in our periodically heated imposed flow. Thermal and dynamics modeling of the problem were made by a computational fluid dynamics (CFD) calculation, based on the finite volume method to model both the fluid flow and heat transfer. To take account of the strong temperature gradient and velocity near the walls, we chose a structured tight mesh near the walls and a little wider mesh elsewhere. The results have shown that for Grh > 4 × 108, the flow regime is laminar, while for Grh > 109, the flow regime becomes turbulent.