Nabil Bougherira

The majority of thermal sources in northeastern of Algeria, is home to a large number of Hammams (spas) with high geothermal potential (El Tarf; Guelma, Souk Ahras, and Skikda). These thermal springs fall into the low temperature category (between 30°C and 150°C), however Hammam Debagh's source...

Drought is considered a natural hazard and has become a recurrent phenomenon in Algeria since the 1970s. Algeria is characterized by three different climates, namely, sub-humid, semi-arid and arid climates. In this study, we aimed to spatiotemporally assess drought hazard, vulnerability and risk in the three climates of three sub-basins, namely, the Seybouse Maritime, Wadi Djelfa-Hadjia and Wadi M’Zi sub-basins. To this end, the standardized precipitation index (SPI) and the reconnaissance drought index (RDI) were used to evaluate drought physical characteristics on a 12-month timescale, based on precipitation and temperature monthly data covering the period of 1979–2019. High values of the coefficient of determination (R²) (0.76–0.99) confirmed by low values of the root-mean-square error (RMSE) (0.08–0.49) proved that the drought indices displayed a high correlation. Drought hazard and vulnerability were evaluated based on physical characteristics and socioeconomic aspects, respectively. The results led to the determination of a high correlation between the two indices used; the determination of the main drought events; and the mapping of the drought hazard, vulnerability and risk using a geographic information system (GIS). These findings suggest that the SPI provided the highest intensities, while the longest periods and the strongest magnitudes were given by the RDI. The spatiotemporal drought distributions varied with time from station to station and from sub-basin to sub-basin. Risk maps revealed that vulnerability based on socioeconomic factors controls drought risk.

Algeria has established a growing urban pole, therefore urbanization and urban dynamics are increasing from year to another, and it occurs a flow of excessive urban wastewater discharges from these agglomerations.In this research, we are interested in the evaluation of the current state of wastewater, which comes from 1114 residences by household activities and human metabolism, or the mixing of domestic wastewater with water runoff.In the extreme North east of Algeria, the predominantly domestic waters of Drâa-Errich city, evacuated through collectors and without treatment they are rejected in nature, and the quality of the water at the level of the Gueridjima wadi has deteriorated and these waters currently constitute a polluted effluent which joins the waters of the El Aneb wadi to the west. A set of analyzes was carried out (period of April to May 2021) on domestic wastewater to assess their quality.Sampling and analysis carried out of surface water (02 samples from Gueridjima wadi and 02 samples from El Aneb wadi) and groundwater (01 well), covering an area of 15 km.The physic-chemical parameters measured with the WTW multiparameter are pH, temperature, electrical conductivity EC, biological demand in oxygen BOD5. In addition, the undesirable substances are Nitrates (NO3-), Nitrites (NO2-), Phosphates (PO4-), and orthophosphate.In front of this situation, the measures proposed are the systems for treating domestic wastewater sewage, seen the advantages represented by the topography of the land in the region; remains the better solution for possible reuse recovery of wastewater, in agriculture sector. This measure will certainly improve the quality in terms of production of an acceptable quality of (purified) wastewater, and reduce environmental problemsKeywords: current state - domestic wastewater - sewage - admissible quality.

Azzaba region contains a mining sector that was created in 1971 and operated until 2006, during this period huge quantities of mining residues were released in nature without any environmental rehabilitation plan which certainly deteriorated surface and groundwater quality by trace metals menacing the people’s health as well as the aquatic ecosystems in this zone. The purpose of this study is to illustrate and to assess the surface and groundwater pollution toward heavy metals at the vicinity of the abandoned mining site. The primary analysis aimed to evaluate the pollution due to mercury in the region after many years of the closure of the mining industry to compare it with evaluations made during its operational period. In addition, further analyses of water pollution toward heavy metals usually used in the mercury industry (iron, zinc and copper) and probably released in the Fendek Wadi were conducted. These analyses allowed characterizing the ecological state of the studied environment by highlighting the concentrations of trace elements (mercury, iron, zinc, copper). According to the analyses, most of these concentrations meet the World Health Organization (WHO) standards; in fact only iron concentration exceeds them at the stations P7 and P8. Finally, the study results were compared by those obtained by previous studies; it was found that the mercury concentration has decreased with time which means that the contamination danger is disappearing.