Abstract
Despite growing concerns over water scarcity and quality degradation in semi‐arid Algeria, few studies integrate water quality indices with multivariate analysis to assess irrigation suitability and identify pollution drivers. This study addresses that gap through an integrated spatial assessment of surface water quality using water quality index (WQI) and multivariate statistics. Water samples were collected monthly from March 2023 to February 2024 across seven monitoring stations, yielding 84 measurements. Results revealed spatially heterogeneous degradation, with station S4 emerging as the most critical contamination hotspot, while the remaining stations, including S3, showed comparatively lower deterioration. S4 recorded an electrical conductivity of 7515 μS/cm, exceeding recommended thresholds, alongside sodium concentrations above 960 mg/L, a sodium adsorption ratio of 16.23 and a Kelly's ratio of 3.14, indicating high sodicity and unsuitability for irrigation. Such salinity can impede plant water uptake, causing water stress and reduced yields. Elevated nitrates (73.63 mg/L) and phosphates (278.26 mg/L) suggest pollution from excessive fertilizer use and inadequate wastewater management, raising eutrophication risks. These findings support targeted monitoring of S4, improved irrigation practices, salt‐tolerant crop selection and sustainable water management strategies in the Mila region, underscoring the urgent need for integrated water resource management.