Hydrogeological and water quality analysis of thermal springs in the Guelma region of North-Eastern Algeria: A study using hydrochemical, statistical, and isotopic approaches

Abstract

This study aimed to investigate the hydrogeological features of aquifers in the Guelma Basin using hydrochemical, statistical, and isotopic analyses. The hydrochemical facies of phreatic waters were determined by analyzing 13 parameters of 14 water samples, and correlations between mineralization and contributing elements were identified through statistical analysis. Isotopic analysis was utilized to establish the groundwater's origin. The results showed that water in the Guelma Basin is generally hard, with varying levels of mineralization ranging from significant to excessive. Water quality worsens progressively as it flows in the direction of groundwater flow, particularly in the post-nappe domain due to water/rock interaction. Furthermore, the hydrochemical facies of phreatic waters differed based on their location, with calcium bicarbonates in the upstream and calcium chlorides in the downstream. Through statistical analysis, the study found that mineralization is positively correlated with elements contributing to mineralization, such as Na+ and Cl-. Electrical conductivity (CE) and Residual Salt (RS) were also positively correlated with these ions. Isotopic analysis revealed that the groundwater in the area has an old origin, and the δ2H and δ18O relationship identified mixing effects in the multi-aquifer system. Additionally, the upward movement of thermal water from deep to shallow aquifers is likely due to the abundance of fractures and faults in the research area. This study provides valuable insights into the hydrogeological characteristics of aquifers in the Guelma Basin and can inform future planning related to water, agriculture, or industry in the region. By using hydrochemical, statistical, and isotopic approaches, the researchers were able to determine the origin and movement of groundwater in the area, which can be useful for future decision-making. Overall, the study highlights the importance of understanding the hydrogeological characteristics of aquifers to make informed decisions regarding water management and resource utilization.