Search

This study was carried out to investigate the current status of surface water and groundwater quality in Lower Seybouse and Annaba Plain, NE Algeria. 36 surface water and groundwater samples were collected in this area, and various physicochemical parameters were analysed. The quality of surface water and groundwater for drinking and the associated health risks were assessed using a Water Quality Index (WQI) and a Human Health Risk Assessment (HHRA) model. The results show that all samples are alkaline with the EC values ranging from 1139 to 5555 µS/cm. The ionic dominance pattern was in the order of Na+ > Mg2+ > Ca2+ > K+ for cations and Cl- > HCO3 - > SO4 2- > NO3 - for anions, respectively. The dominant water types are SO4-Cl-Ca-Mg and SO4-Cl-Na, formed by dissolution of evaporative and carbonate-rich material. All samples are unsuitable for drinking, with 1 sample classified as poor (rank = 4) and 35 samples as extremely poor (rank = 5). These samples are mainly located near the Seybouse Wadi, which is a natural outlet for wastewater from human activities. The assessment of non-carcinogenic risk showed that the Hazard Index (HI) for males ranged from 0.12 to 1.01 with a mean of 0.30 and only one sample exceeded value 1. For females, the HI was between 0.16 and 1.28 for females, with a mean of 0.39. The risk for children was even higher, ranging from 0.41 to 3.28, with a mean of 1.03, suggesting that children are more vulnerable to water contamination. The Carcinogenic Risk (CR) values for Pb ranged from 10-3 to 8.6 · 10-3, with a mean of 2.6 · 10-3 for males, and between 1.4 · 10-3 to 10-2, with a mean of 3.3 · 10-3 for females, while for children the CR values ranged from 3.5 · 10-3 to 2.7 · 10-3, with a mean of 8.4 · 10-3, indicating that no possible CR from water drinking. [ABSTRACT FROM AUTHOR]

This study was aimed at determining the concentrations of all chemical elements in iron-rich ore from the Gara Djebillet region in Algeria using instrumental neutron activation and spectroscopic analysis. Samples from four sites in the region were analyzed by spectroscopic methods such as X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning microscopy (SM). In addition, instrumental neutron activation analysis (INAA) allowed for a complete quantitative characterization of the ore. Results showed that there were forty-two elements found in trace and ultra-trace amounts and which were equally exploitable. The iron-rich deposits of the region are of great economic value to the country. [ABSTRACT FROM AUTHOR]

The purpose of this study is to evaluate the quality of groundwater used for irrigating agricultural areas in the region of Ouargla by using several quality indices and to map the spatial distribution of these indices. This spatial mapping will help create a model for the classification of these resources according to their suitability for irrigation. For this purpose, physicochemical analyses were carried out on samples from 38 wells distributed over the entire territory of the studied region. These include 27 wells that capture Mio-Pliocene groundwater (Terminal Complex) and 11 wells in the Albian groundwater (Intercalary Continental). The thematic maps were developed using a geographic information system (GIS). In this study, we used the following eight indices: potential salinity (PS); residual sodium carbonate (RSC); electrical conductivity (EC); magnesium percent (%Mg2+); sodium percent (%Na+); permeability index (PI); Kelley's ratio (KR); sodium adsorption ratio (SAR). The global qualitative study of the water used for irrigation shows that these resources fall into three categories (good, permissible, and poor for irrigation). Water quality analysis shows that, based on the magnesium percent (%Mg2+), 18% of the wells can be considered to be of good quality, 74% of the wells are of medium quality (permissible for irrigation), and 8% are of poor quality (unsuitable for irrigation). According to the Wilcox diagram, the waters used in the Ouargla region are of very poor quality. Very excessive mineralization, expressed by the electrical conductivity, was observed for the Mio-Pliocene and Albian waters, where it varies with values in the range of 2340 µS/m to 6520 µS/m and 2330 µS/m to 3840 µS/m, respectively. This conductivity presents a high risk of alkalinization. [ABSTRACT FROM AUTHOR]

The North-Western Sahara Aquifer System (NWSAS) is a complex multi-layered aquifer system with extraordinary continental groundwater reserves. This largest aquifer in the world straddles three countries: Algeria, Libya, and Tunisia. It contains more than 50,000 billion cubic meters of water; of which 70% is in Algerian territory in the southeast of the country. This water is the result of accumulation over 1 million years. In the Wadi Mya basin (Algeria), this system is characterized by two overlaid aquifer systems: the complex terminal (CT), a shallow aquifer housed in the Senonian-Eocene and Mio-Pliocene formations, and the continental intercalary (CI), a deep aquifer hosted in the Albian, Aptian and Barremian formations. The main purpose of this study is to carry out a correlation between the geochemical composition of the water and the facies of the aquifer formation. The adopted approach will allow deciphering the hydro-chemical relationships between the different levels of the two aquifer systems in the Wadi Mya basin. To acquire the chemical composition of water, the study method goes through a targeted sampling and physicochemical analysis of water followed by a statistical analysis as well as correlation and geochemical modelling: the interpretation of specific diagrams (Piper), correlations between chemical elements in binary graphs, and principal component analysis (PCA). The performed geochemical modelling by examining the saturation index and chemical balance of water helps to better understand the origin of mineralization, elucidate the mixing of waters originating from different aquifers, as well as highlight the relationship between deep and shallow aquifers in the Wadi Mya Basin hydrodynamic conversion. The obtained results indicate that the overall mineralization occurring within the study area is dominated by sodium chloride and calcium chloride-sulfate facies. This can be explained by the dissolution of halite, gypsum, and anhydrite evaporitic rocks, intercalated in the aquifer matrix besides the effects of the extended stay of fossil waters with low recharging and cation exchange reactions resulting from water-rock interactions. The interference recorded between the geochemical signatures of the two aquifers favors the hypothesis of interconnection between aquifers through fractures. Through the implementation of such academic research, this invaluable source of life will stay sustainable for future generations. [ABSTRACT FROM AUTHOR]

Groundwater is the main resource used to meet the people's drinking water and irrigation needs of the Ain Oussera plain, because of the lack of surface-water resources. This paper intended to evaluate the suitability of groundwater for agriculture and drinking in the Ain Oussera plains. The data of the study were gathered and analyzed from twenty (20) groundwater samples collected to assess the plain groundwater quality, using the Water Quality Index (WQI) and GIS, carried out on physico-chemical parameters, including potential of hydrogen (pH), total dissolved solids (TDS) electrical conductivity (EC), potassium (K+), sodium (Na+), magnesium (Mg2+), and calcium (Ca2+) and major anions (Cl, HCO3, NO3, SO4), as well as, the water suitability test for agricultural purposes, using the sodium adsorption ratio. These parameters were inserted into the GIS platform to create a spatial distribution map for each parameter using the inverse interpolation technique (IDW). The results indicated that the concentrations are within the Algerian permissible limits. The water quality index (WQI), which evaluates the suitability of water for consumption, varies from 31 to 173 with an average value of 81. 70% of the samples from the Ain Oussera plain fall within the excellent and good quality categories. Its water is suitable for consumption (WQI < 100), while 30% is in the poor water category. From the calculation of SAR values, it was found that 90% of the groundwater samples are considered excellent and suitable for irrigation. According to the classification of the United States Salinity Laboratory USSL, the Ain Oussera water quality is classified as poor for irrigation purposes. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to focus on the assessment of water resources in the Seybouse middle sub-basin. Analyses of water and various current uses are used to draw attention to the necessity of implementing water resources integrated management into a plan aiming at a rational exploitation. Design/methodology/approach – Any sustainable management of water resources is closely dependent on the ability to accurately assess the quantity and quality of available water resources that are used as water supply for the population, agricultural production, industrial or energy. The analyzed and processed available data serve as database for integrated water resources management. Findings – Analysis shows that the annual water supply is represented by 71 percent of the surface water resources and 29 percent of groundwater. The total volume of water used in the middle Seybouse basin is estimated at 36.22 hm3/yr. The predicted water needs are estimated to 79.19 hm3/yr in 2030. The groundwater of the Guelma alluvial aquifer exhibits a calcium chloride-facies general trend. The evolution of the chemical elements is related mainly to the geological nature of the reservoir lithologies. The heavy metals do not exhibit clear anomalies, but the surface water of the majority of streams is heavily infected with bacterial germs. Practical implications – The obtained results show that the Seybouse middle sub-basin needs twice as much water by 2030 for the different uses. This requires a better management of water resources for a sustainable development in this specific region of Eastern Algeria. Originality/value – This paper is devoted to the management of water resources in a specific region (the middle Seybouse basin) which constitutes an interesting example of considerations to be taken for a sustainable development. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the possibility of applying multilayer perceptron neural network (MLPNN) and cluster analysis approaches for rebuilding non-cored lithofacies. These techniques are carried out to predict missing lithofacies intervals from the reservoir of Trias Argileux Grèseux Inférieur in the Sif Fatima oil field (Berkine basin- Southern Algeria). The performances of the suggested models were evaluated using root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (R). The MLPNN model was developed using four input variables of nuclear well logging data including: Gamma-Ray, Density, Potassium and Thorium. MLPNN model shows lower RMSE and MAE with 0.39 and 0.23 respectively, together with strong R values (training = 0.87; validation = 0.78; test = 0.92). The cluster analysis model displays lower performances (R = 0.68, RMSE = 1.04 and MAE = 0.54). This quantitative comparison between real and predicted electrofacies using the two methods indicates that MLPNN model is more recommended in rebuilding non-cored lithofacies than cluster analysis. The MLPNN model makes possible to estimate lithofacies in 333 m of non-cored lithofacies allowing an important economic benefit. • Multilayer perceptron neural network and cluster analysis methods are used to rebuild lithofacies based on nuclear logging. • MLPNN model with architecture of (4-4-4) is highly recommended showing high performances. • The study allows recognizing of missing lithological facies for 333 m in non-cored intervals. • Predicting of non-cored lithofacies with MLPNN has an important economic benefit. [ABSTRACT FROM AUTHOR]