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In the recent years, the coastal aquifer of Jijel plain (North Algeria) located on the south of the Mediterranean Sea was utilized for cities growth and agricultural development of the region. Consequently, overexploitation and seawater intrusion were identified as major risks to the groundwater resource. In this work, a new approach integrating groundwater vulnerability method and numerical model for predicting the actual and future seawater is proposed. The groundwater vulnerability assessment has been performed by applying the GALDIT method using GIS and the MODFLOW model was used to simulate the actual and future groundwater level of the aquifer over the period 2020-2050. Three scenarios were simulated under water demand and climate conditions (drought, recharge) to obtain the changes in the groundwater level variation. The results of the GALDIT model application to the actual conditions (year 2020) showed that the high class of groundwater vulnerability is located in the coastal fringe and the terminal stretches of wadis where the seawater intrusion limit is located at a distance range between 840 and 1420m from the shoreline. However, the results for predicting future groundwater vulnerability showed that the scenario which proposed the artificial recharge basins, although predicting a worrying situation compared to the actual condition, has the best figure of the groundwater vulnerability assessment and seawater intrusion despite the other two scenarios. In this case the limit in the year 2050 is located between distances of 850-1640m from the shoreline with a forward speed of seawater intrusion of 1-8m/year, compared to the reference year 2020. This showed that groundwater level variation and recharge were the key factors in controlling groundwater vulnerability to seawater intrusion. The presented new approach can be used to mapping the actual and future groundwater vulnerability assessment to seawater intrusion and groundwater resources management in any coastal areas worldwide.

After more than a year from the first confirmed cases of coronavirus (COVID-19) disease, the role of meteorological factors in the transmission of the virus still needs to be correctly determined. In this scenario of deep uncertainty, the present study aims to investigate the effects of temperature and relative humidity on daily new cases of COVID-19. For this purpose, the COVID-19’s development of infection in fourteen Algerian cities characterized by different climatic conditions, during the period from April 1, 2020, to August 31, 2020, has been investigated. A detailed time series analysis along with linear regression was used to state a possible correlation among some climate’s factor variability (temperature and relative humidity) and daily new confirmed cases of COVID-19. The results showed a weak correlation between daily new cases of COVID-19 and meteorological factors throughout the selected regions.In addition, we concluded that the COVID-19 could fit to high or low values of temperature and relative humidity, and other factors not climates could affect the spreading of the virus like demography and human contact. So, after the discovery of the vaccine and before vaccination of 70% of the world’s population, living with the virus has become an inevitable reality, and it is mandatory to apply the sanitary procedures to slow down the COVID-19 transmission. Graphical abstract: [Figure not available: see fulltext.]

In a basin, the increase of the water demand in all sectors creates a giant problem of water scarcity. Precipitation is the only major source to mitigate this problem. However, groundwater recharge is an important hydrological parameter for the quantification of the water budgets quantification in order to achieve a better sustainable groundwater management. In the Macta basin (Western Algeria), the average annual precipitation is insufficient in most of the part especially during summer season. In this region, the recharge is a difficult parameter to calculate due to its variabilities: climatic, geological, hydrogeological, soil, etc. The aim of this study is to propose a new method of identifying potential recharge zone which is applicable to watersheds. For this study and in order to identify the potential groundwater recharge areas in the Macta watershed, a new method has been applied. In this approach, two considerations must be taken into account for the selection of potential recharge areas, remote sensing and GIS which allow the analysis of the water harvesting structure for extracting the information of various features such as lineament, land use/land cover, soil, slope, lithology, drainage, rainfall, etc. In order of importance, we have assigned weights for each feature. Slope and design discharge are parameters’ key in site suitable analysis, so we assigned a maximum weight to this parameters. A possible suitable map site for water harvesting/conservation structures was derived following an analytical hierarchy process (AHP) and multi-criteria decision analysis (MCDA). The data are combined through a multi-criteria analysis to facilitate the spatial analysis and the identification of appropriate zones recharge areas. The results indicate that potential areas of high recharge account for about 32% of the total watershed area. They are mainly located in the south center and appear fragmented in the north of watershed, which mainly match to the permeable areas. These results depict the groundwater potential zones in the study area and provide the information for the proper planning and groundwater resources management.

This study presents hydrochemical analysis and geothermal evaluation of thermal springs located in north central Algeria for possible exploitation in agriculture, greenhouses, and residential heating. The exploitation of this energy depends on geothermal water parameters such as T°, pH, flow rate, and thermal power. Thirty one thermal springs were identified in our study area including Ouarsenis, Biban, and Kabylie provinces in the Tell Atlas, northern Algeria. These thermal springs are included by hammams, baths, and spas with hot waters exhibiting a mean temperature of 60 °C. Samples were collected during March 2018 on the thirty-one sites to evaluate the hydrochemical properties of hot waters and physicochemical parameters were measured in situ. The results show that the geothermal temperature of the reservoir in the study area is of approximately 130 °C. The temperature of hot waters varied between 22 and 80 °C. The pH revealed that the hot waters are acid; the flow rate varied from 0.8 to 30 L/s. The thermal power water calculated for all sites is ranged between 40 and 5020 KWth. This study is a part of a project related to a new global mapping of thermal spring parameters with corresponding geothermal energy potential. This potential is important for sustainable development by introducing geothermal energy instead of fossil energy.

The aim of this study is to provide detailed geological and structural information about groundwater aquifers in the Chott Ech Chergui region using geophysical and remote sensing data. The Chott Chergui region is a large endorheic depression situated in the northwestern part of Algeria. It is submerged in water, and for that reason, it is considered to be a humid zone even though the region is considered to be a semiarid area. The largest quantities of water come from the northern mountains of Saida and Tlemcen. Some water recharge comes from the Ksour and Amour mountains to the south. Large amounts of this water reach the underground aquifers through a dense fracture network. These water resources are stored in a lithological complex that is composed of three closely related aquifer formations, namely, the continental Tertiary aquifer, the Senonian aquifer and the Aaleno-Bathonian aquifer. The Kheiter and Ain Skhouna areas are known for their gushing water springs that exhibit high flow rates (80 l/s for Ain Skhouna). It is for this reason that we focus on these two regions to understand their flow mechanisms and attempt to construct a conceptual model that illustrates the functional mechanism of the Ain Skhouna spring. This work was accomplished employing a combined approach involving Remote Sensing method and electrical resistivity, specifically, the vertical electrical sounding (VES) technique. The VES technique was used to understand the aquifer geometries and their spatial extents, while the remote sensing results were used to detect some structures and lineaments that favor groundwater exploration. The aquifer geometry was analysed by integrating the results obtained from the interpretations of VES with stratigraphic columns of wells and boreholes using a geographic information system. The results of this study show that three geological levels present aquifer potentialities. The geologic zones are the Aaleno-Bathonian aquifer, which is the most important aquifer in the study area with an average thickness of 250 m, the Senonian aquifer and Tertiary aquifer. The aquifers recharge mainly from fractures in the Saida and Tlemcen Mountains for the Aaleno-Bathonian aquifer, and from direct infiltration from the accumulated surface waters for the Senonian and Tertiary aquifers. Many water sources are sporadically distributed in the Chott Ech Chergui, but the gushing waters seems to be controlled by E-W accidents, especially in Ain Skhouna hot spring. A schematic model of the spring is presented.