This study focuses on mapping the groundwater’s vulnerability to pollution in the region of Ouargla, located in the North-East of the northern Sahara, exposed to potential risks of alteration. By applying the methods (GOD, DRASTIC, and SINTACS), coupled with a Geographic Information System (GIS), we were able to identify a medium to high vulnerability trend. In light of the results recorded, the DRASTIC and SINTACS methods prove to be more suitable for our study region. This makes it possible to highlight the recharge zones and land use as being the most vulnerable in the territory studied. The GOD method presents a strong vulnerability trend over 77.02% of the study area. Such a result is directly related to the depth of the water table. It can therefore be argued that this method is far from being representative of the reality on the ground because of these very heterogeneous characteristics.

Groundwater hydrochemistry of Algerian Sahara (Southwest, Algeria) was used to assess groundwater quality to de-termine its suitability for drinking and agricultural purposes. A total of 26 groundwater samples were analysed for 14 para-meters. Standards laboratory methods were used to determine physicochemical groundwater properties. This study shows that these pH, electric conductivity, total hardness, bicarbonate, and phosphate were within WHO limits. The concentration of magnesium ranging from 30.49 to 120 mg∙dm–3 with an average value of 67.21 mg∙dm–3. 38.56% of the water points analysed have a concentration lower than the value set by the WHO at 75.00 mg∙dm–3. It also showed that 70% of the points studied have potassium concentrations that exceed World Health Organization standards. Groundwater of Algerian Sahara is low in nitrogen (NO3–) and the higher concentration may result in various health risks. The result for this study showed that the water was to be found suitable for drinking purposes except for few samples. Piper diagram indicates that groundwater in Adrar belongs to chlorinated-sulphated, sodium and magnesium facies. The groundwater samples of Adrar present high salinity and low alkalinity fall into the field of C3S1 and C3S2. Based on the RSC values, all samples had values less than 1.25 and were good for irrigation.

Sand drifting on road networks in the region of the Lower Algerian Sahara is one of the main problems for the sector. Machines are repeatedly deployed to overcome this phenomenon. The long experience acquired while dealing with the removal of sand from roads pushed us to focus on obstacles called "Draas". The purpose of this study is to perform an optimization of these special protective structures called “Draas”, using a reduced physical model. Model tests were performed in flow channel. The principle of modeling the wind transport using a reduced model is to simulate the wind using a liquid stream while respecting the laws of hydraulic and sedimentological similarity. The results obtained are extrapolated to make a normal size prototype.