Groundwater is a crucial natural resource, particularly in arid and semi-arid regions, where it serves as a primary source for drinking and irrigation. The K'sob watershed in Algeria is significant for its groundwater resources. This study aims to assess the ground-water quality of the K'sob aquifer and investigate the spatial distribution of quality parameters to identify areas with the best drinking water quality. The study combines the Water Quality Index (WQI) and Geographic Information System (GIS) methodologies. Twenty groundwater samples were collected and analyzed for major cations and anions. Spatial distribution maps of parameters including pH, temperature (T?), electrical conductivity (EC), total hardness (TH), turbidity, total alkalinity (TAC), chloride (Cl-), nitrate (NO3-), bicarbonate (HCO3-), calcium (Ca2+), and magnesium (Mg2+) were created using the Inverse Distance Weighted (IDW) interpolation method in a GIS environment. The WQI results revealed temporal variations in groundwater quality between 2022 and 2024. In 2022, 5% of samples were of excellent quality, 60% good quality, 15% poor quality, 5% very poor quality, and 15% unsuitable for drinking purposes. By 2024, samples classified as excellent quality increased to 25%, while good quality samples decreased to 35%. Poor quality samples remained stable at 15%, very poor quality samples increased to 10%, and those unsuitable for drinking remained at 15%. This research demonstrates the effective combination of GIS and WQI in assessing groundwater quality over space and time. The findings can support decision-makers in planning the operation and management of groundwater resources.
Tiaiba et al. (Wed,) studied this question.