Résumé: The current study was conducted to classify the quality of groundwater in wetlands. This research was carried out to evaluate the groundwater quality of wells in the surrounding area according to the Irrigation Water Quality Index (IWQI) to verify its suitability for agricultural purposes. The IWQI was developed in 2010 by Meireles; it was calculated based on the water quality parameters: EC, Na+1, Mg+2, Ca+2, Cl–1, and HCO3- of 37 monitoring wells. The results of the IWQI show that the water quality declined significantly in July, with the majority of wells 76% within the severe restriction category (SR), which means that it’s suitable only for irrigation of crops with high salt tolerance, and 14% of wells falling within the High Restriction category (HR). The lake’s discharge decreases during the dry season, and most of the water quality classified as a severe restriction (SR), this indicates that the groundwater is influenced by the saline waters of Lake Fetzara, which are already loaded with chemical elements due to evaporation. As a result, the study of groundwater suitability for irrigation revealed that these waters are generally acceptable for irrigation of salt-tolerant crops on well-drained soils but require a prior control of salinity evolution.

Résumé: A comparative assessment of water quality for drinking purposes was conducted in Ain Larbi area using the Weighted Arithmetic Water Quality Index (WA-WQI). The origin of minerals is assessed by a saturation index approach and the Gibbs diagram. Also, mineral correlation process and ion exchange mechanism are detected by the Principal Component Analysis (PCA). The PCA results indicate that the groundwater quality in the Ain Larbi study area primarily results from weathering and geochemical alteration of rock. The saturation index and Gibbs diagram support these findings. The WA-WQI was calculated for each station based on physicochemical parameters. During the wet season, three out of five classes of WQI were observed in the present study, including excellent (25%), good (70%), and poor (5%). In the dry season, the classes excellent (25%), good (30%), and poor (45%) were represented. The present situation demonstrates how hydrogeological regimes and water–rock interactions affect groundwater ion concentrations. Our results contribute to identifying drinking water requirements in the Ain Larbi region, promoting sustainable water management.

Résumé: This article presents an approach to the assessment of the environmental impact of a dam construction for agricultural use in the Boutheldja region. This region’s environment is rich in natural resources and forms a part of the El Kala National Park (P.N.E.K). It was designated a wetland of international importance under the Ramsar convention by UNESCO in 1983 and later declared a biosphere reserve in 1990. It is among the most significant aquatic areas in this region (contains about 40% of surface water resources). The physical characteristics of the watershed support the construction of the dam, although there could be a number of unfavorable effects: upstream – including soil erosion and reservoir sedimentation, reduced storage capacity, lower water quality and loss of productivity of flooded area; downstream – removal of silt from downstream flows, loss of fertilising functions, changes in water quality, changes in productivity, reduction in natural floods, loss of access to resources and ecological disturbance. Such processes will have an impact on an ecosystem so fragile. Although Boukhroufa dam provides significant benefits to the city, such as controlling stream regime, preventing floods, and supplying agricultural water from stored water, it also has significant negative effects on the surrounding watershed ecosystem.

Résumé: In the Drean-Annaba alluvial aquifer, the water quality often fluctuates. Water-rock interactions cannot be the main cause of the observed changes, but the country’s dryness during the last two decades has played a significant role in water quality changes. During this time, abnormalities in the timing and distribution of rainfall events were detected. As a result, hydrochemical changes in groundwater and surface water, such as wadis, have a predictable pattern. To demonstrate these chemical effects statistically, principal component analysis (PCA) tools and a nickel diagram were used. The findings corroborate seasonal fluctuations in water quality between 1999 and 2000. The competition between alkaline and alkaline earths can be seen from a cationic standpoint. On the other hand, there is a shift from chlorides to sulfates and possibly to bicarbonates from an anionic standpoint. The isotopic technique revealed neo-salinity whose source was unknown. The current study was conducted in a small area, which was beneficial for demonstrating the relationship between dryness and water quality in both the aquifer system and surface water. This study investigated the complex dynamics of water salinity within the Seybouse Basin, offering insights into its distribution, origins, and implications for groundwater management. Through a multidisciplinary approach encompassing hydrochemical analyses, mineralization mapping, and isotopic investigations, we elucidate significant patterns governing groundwater quality in the region. Our findings reveal the intricate interplay of factors such as marine intrusion, evaporation, and geological formations in shaping salinity levels across various water sources. The spatial variations highlighted through mineralization mapping and Br/Cl ratio analysis underscore the nuanced nature of marine intrusion along the coast, which is influenced by hydrodynamic factors and geological features. The identification of distinct salinity families based on conductivity and isotopic signatures underscores the diverse mechanisms contributing to water salinity, from evaporation-induced conductivity changes to the effects of recent heating. This research underscores the importance of interdisciplinary approaches in understanding groundwater systems and informs critical considerations for water resource management and sustainability efforts in the Seybouse basin and similar regions. By leveraging the insights gleaned from our study, stakeholders can develop targeted strategies to mitigate salinity-related risks and ensure the sustainable utilization of water resources.