Perrin Jean-Louis auteur aut IRD Rais N. auteur aut IRD Chahinian Nanée auteur aut IRD Moulin P. auteur aut IRD Ijjaali M. auteur aut IRD text journalArticle eng text/pdf born digital access Oued Fez (one of the Sebou River tributaries - Morocco) allowed us to study and quantify the effect of the lack of wastewater treatment on surface water quality in semi-arid hydrological context. The analysis is based on field data collected from June 2009 to December 2011. Concentration and load patterns of nitrogen, phosphorus and chromium (used in the processing of leather) are compared in stable hydrological conditions during low flow and high flow periods in an eight-location sampling network. The Oued Fez and the Sebou River are characterised by severe pollution downstream from the city of Fez, particularly TN (mainly NH4 and N-org), TP (mainly P-part) and TCr. The most polluted sites are those directly under the influence of domestic and industrial waste water inputs, particularly tannery effluents. Obviously, the concentrations measured at these locations are above all environmental quality standards. Pollutant loads are very heavy in the Sebou River and can contaminate the river course for kilometres. Moreover, as the water of the Sebou River is used for the irrigation of vegetables, serious problems of public health could arise. A better understanding of contaminant dynamics and self-purifying processes in these rivers will help implement actions and steps aimed at improving water quality in the Sebou River, which is the primary water supply source in Morocco and is used for agricultural and industrials purposes as well as for drinking water. specialized Water quality Nutrients and chromium Waste water effluents Spatial and temporal variations Fez Morocco MAROC 062 038 510 26-34 2014 0022-1694 https://www.documentation.ird.fr/hor/PAR00011667 10.1016/j.jhydrol.2013.12.002 0022-1694 [F B010061874] https://www.documentation.ird.fr/hor/PAR00011667 https://www.documentation.ird.fr/intranet/publi/2014/04/010061874.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2014-04-29 2017-08-23 PAR00011667 fre