Résumé
This study aims to characterise and quantify the pollutant concentrations and fluxes in various locations of the Oued Fez hydrological network and assess their impact on the Sebou River, which is considered as a national priority zone in Morocco. Eight observation sites have been set up to quantify the temporal and spatial variability of pollutant fluxes in the river and to rank water and pollutant contributors. Water quality is evaluated through nutrients (total nitrogen and total phosphorus essentially) and heavy metals (essentially chromium). The results show that the river is highly polluted: the measured concentration values exceed international water quality standards for all the studied elements and indicate that the river is a possible threat to the downstream water bodies of high economic interest.