Geochemical characteristics of the continental waters downstream from the Bou Regreg basin and the Temara Plain in Morocco

摘要

In the final section of the Bou Regreg fiver basin (Northern Morocco) a rapidly expanding process of urbanization is in progress, due to its proximity to Rabat, the capital of the Kingdom. This study focuses on the chemical quality of surface and groundwaters in an area affected by anthropogenic sources of pollution from a waste dump and agricultural activities. On a set of 33 water samples, main components and selected trace elements were analyzed. Geochemical classification of the waters was carried out. The water quality deterioration is mainly due to the tidal sea water intrusion into the river up to 24 km upstream from its estuary on the ocean. This salty water feeds the shallow aquifer nearest to the river. This study indicates that there is not, except for mercury, significant release of heavy metals from the waste dump. The shallow waters also show the common contamination by agricultural fertilizers with, at times, high values of nitrates in irrigated areas. Contamination from mercury, probably due to the presence of salts of this element in pesticides, was also found in some wells.