Assessment of Surface Water Quality Using the Water Quality Index (IWQ), Multivariate Statistical Analysis (MSA) and Geographic Information System (GIS) in Oued Laou Mediterranean Watershed, Morocco

Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality crucial irrigation, human welfare, health. Thus, the main objective to improve surface assessment geochemical analysis evaluate anthropogenic activities’ impact on in Oued Laou watershed, Northern Morocco. Thirteen samples were characterized 26 physicochemical biological parameters. In this aspect, emerging techniques such as multivariate statistical approaches (MSA), indices (WQI), irrigation (IWQI), Geographic Information System (GIS) employed identify sources pollution, their suitability consumption, distribution quality. The results showed that major ion concentrations reported following order: Ca2+, Na+, Mg2+, K+; HCO3− > CO32− Cl− SO42− NO3− F− PO43− NO2−. It was also demonstrated almost all parameters had lower than World Health Organization (WHO) limits, except bicarbonate ions (HCO3−) biochemical oxygen demand five days (BOD5), which exceeded WHO limits at 120 mg/L 3 mg/L, respectively. Furthermore, types Ca2+-HCO3− (Calcium-Bicarbonate) Ca2+-Mg2+-HCO3− (Calcium-Magnesium-Bicarbonate) predominated water. Principal Component Analysis (PCA) indicates river exposed two forms contamination, first being attributed activities while second reflects water-sediment interaction. Hierarchical Cluster (HCA), reflecting mineralization study area, has classified into four clusters. Inverse Distance Weighting (IDW) WQI 7.69% 38.46% represent, respectively, excellent good drinking. At same time, IWQI revealed 92.30% irrigation. As result, combination WQIs, PCA, IWQI, GIS effective providing clear information assessing controlling factors can support decision-making susceptible locations northern