M. MEZALI Farouk

Groundwater recharge is critical for sustainable water management in water-scarce regions like North Algeria, where climate change and urbanization exacerbate resource challenges, particularly in the populous Algiers watershed. This study evaluates groundwater recharge potential using the Analytical Hierarchy Process (AHP) and its fuzzy extension (FAHP), integrated with Geographic Information Systems (GIS), to map recharge zones. Employing open-source data, AHP and FAHP assessed factors such as lithology, slope, and rainfall, classifying the watershed into high, moderate, and low recharge potential zones. Results show AHP identifying 44.01% (528.95 km2) as high, 52.82% (634.93 km2) as moderate, and 3.18% (38.14 km2) as low potential, with FAHP yielding similar outcomes (44.35%, 52.47%, and 3.17%, respectively). Validation using borehole drawdown data confirmed a 73.3% accuracy and an AUC of 0.72, indicating moderate to good reliability. High recharge zones were concentrated in the central and northern areas with permeable soils and gentle slopes, moderate zones dominated the region, and low zones were minimal. This study concludes that both AHP and FAHP are effective for preliminary recharge assessments, with AHP favored for its simplicity, though FAHP excels with uncertain data. Limited high-resolution hydrogeological data highlight the need for further refinement, yet the approach offers a replicable framework for managing groundwater in arid, urbanized regions facing similar environmental pressures.

bstract
Background and objective

Small cerebral aneurysms are currently commonly treated non-invasively by flow diverter device. These stents lead to thrombotic occlusion of the aneurysm soon after their placement. The purpose of this work is to model clotting into intracranial aneurysms with and without stents, using a non-Newtonian of blood behavior, and to investigate the importance of stent to generate desired thrombus in intracranial aneurysms.
Method

The description of blood flow is made by the Boltzmann lattice equations, while thrombosis is modeled by the "fluid age" model. The lattice Boltzmann method is a computational technique for simulating fluid dynamics. The method is based on a mesoscopic approach, where the fluid is represented by a set of particles that move and interact on a grid. The model for blood coagulation is described by lattice Boltzmann Method, and it doesn't take into account the complicated coagulation pathway, this main idea is developed using the model of residence time of blood: all fluid in the domain is assumed to be capable of clotting, given enough time. The fluid age is measured by a passive scalar using a transport equation, and the node coagulates if the fluid age increases enough. Three small aneurysms of different sizes and shapes with three stents of various porosities were used to test the ability of the model to predict thrombosis. The "occlusion rate" parameter is used to assess the effectiveness of the flow diverter device.
Results
For the large aspect ratio factor, the occlusion is: 91% for flow diverter devise with seven struts. For medium aspect ratio, a rate of 80% is achieved. An occlusion rate of slightly more than 30% is obtained for very small aneurysms with low aspect ratio. The Newtonian model underestimates the volume of thrombosis generated. The difference in the prediction of the thrombosis volume between the Newtonian and no-Newtonian Carreau-Yasuda models is approximately 10%.
Conclusion

The occlusion rate is proportional to the aspect ratio form factor. For the large and medium aspect ratio factors, the occlusion is satisfactory. Concerning very small aneurysms with low aspect ratio, aneurysm occlusion is low. This rate can be improved to almost complete occlusion if the flow diverter device is doubled. The generality of the model suggests its extensibility toward any other type of thrombosis (stenosis, thrombosis in aortic aneurysms).

The study aims to evaluate the efficacy of the completed concrete canal in the urban expansion area of the city of M’sila to prevent the flood risks of river Portem, by performing a hydraulic simulation using the 2D river simulation program HEC-RAS 2D and geographic information systems (SIG), in this research and after determining The water catchment, extraction of morphological characteristics, and calculation of the maximum flow quantity Qmaxm 3/s based on the series of rainfall data for the reed station for a period of 37 years after processing it spatially in geographic information systems. The areas exposed to the risk of flooding have a direct relationship with the period of return, so that an area of 9.98 hectares was recorded in the return period of 10 years, 12.72 hectares in 50 years, and 14.31 hectares in 100 years. The study also showed the importance of using HEC- RAS 2D and (SIG) in evaluating the efficiency of the concrete channel to prevent floods and contribute to decision-making to reduce the resulting disasters.

Flooding is one of the most devastating natural disasters brought on by climate change in North Africa. The occurrence of flood risk is due to a combination of natural and man-made variables, necessitating a better knowledge of its spatial scope. The goal of this study is to locate and map flood-prone regions in the Cheliff-Ghrib watershed. Within the ArcGIS interface, this study is based on the integration of multi-criteria data such as slope, drainage density, type of soil, rainfall, population density, land use and sewer system density. For flood risk assessment and mapping, the Analytic Hierarchy Process (AHP) technique was employed as a multi-criteria analysis, allowing the integration of numerous factors under two criteria namely, hazards and vulnerability. The AHP flood risk map reveals that areas at high and extremely high risk of flooding cover 22.5% of the study area. According to the findings, the Cheliff-Ghrib watershed is extremely vulnerable to flooding. Eight of the Chelliff-Ghrib watershed's 15 municipalities (8/15) are at high risk of flooding, necessitating the development of efficient flood mitigation solutions for future flood events.

The flow-diverting stents placement cause the reduction of dynamic flow within aneurysm. The reduction effect is almost the same below five struts (80% of porosity). The results show that, if our objective is restricted to estimating the hemodynamic effect, measured by (velocity, shear rate, occlusion rate), the differences between rheological behavior models are, practically, not significant, and the models can be used indifferently.