Groundwater Quality Assessment in the Coastal Mediterranean Aquifer of Northeastern Morocco - A GIS-Based Approach

Abstract

Groundwater quality degradation is a pressing concern in semi-arid coastal regions, exemplified by the Ghiss-Nekor aquifer in northeastern Morocco, spanning 100 km². This study adopts a comprehensive approach, utilizing Chloro-Alkaline Indices, hydrochemical facies diagrams, the Water Quality Index (WQI), and the Synthetic Pollution Index (SPI) to assess groundwater quality and its evolution. Key findings reveal that Ghiss-Nekor groundwater is brackish, primarily suitable for irrigation due to high Total Dissolved Solids (TDS). Salinization stems from reverse cation exchange, as indicated by hydrochemical analyses. WQI assessments highlight the inadequacy of this groundwater for drinking purposes, with SPI classifying 54% of wells as moderately polluted. Fine particles mitigate marine intrusion in the northwest. Overlaying land-use and electrical conductivity maps identify areas with poor-quality groundwater, notably near an unregulated landfill, a coastal tourist site, and a wastewater treatment facility. Ionic analysis identifies multiple saline sources, with nitrate and sulfate contributions standing out. While the study offers valuable insights, limitations include the need for ongoing data collection and source identification challenges. Nonetheless, the research underscores the urgency of effective water management, particularly around the landfill site situated above permeable deposits, offering an innovative approach with global applicability for addressing groundwater quality issues in semi-arid coastal areas.