Evaluation of the Effects of Riparian Population Activities on the Physicochemical Quality of Water in a Mediterranean River: The Inaouene River (Taza, North East Morocco)

Mediterranean Rivers are often increasingly subjected to stress as a result of riparian population activities. This present study assessed the impact of human activities on the water quality of the Inaouene River in Morocco. For this purpose, water samples were collected from seven sampling stations along the River and analysed. The water of the Inaouene River is characterised by slightly alkaline water pH (7.32-7.59), electrical conductivity (1206.44-3674.14 μS cm-1), very low level of dissolved oxygen (1.98-5.55 mg L-1), BOD5 (45.42-328.7 mg L-1), COD (112.71-468.46 mg L-1). The results classify the Inaouene River’s water in the “moderate to poor” quality range based on Moroccan standards. This water, which is characterised by moderate to severe organic contamination, is also distinguished by a significant allochthone charge from the different riparian urban centres. The multivariate analysis showed a decline in water quality and high amounts of organic matter, nitrogenous and phosphorus in urban centres downstream. Waters from stations located further away from domestic discharge points are less polluted and more oxygenated. Overall, these findings confirmed that the combined effect of anthropogenic activities and the seasonality characteristic of the Inaouene watershed is the main factor that determines water quality.