Evaluation spatiotemporal of the metal contamination of surface water resources in the lower Moulouya (North eastern Morocco) [Evaluation spatiotemporelle de la contamination métallique des ressources hydriques superficielles de la basse Moulouya]

The moulouya basin presents a socioeconomic importance for morocco in general and particularly in the eastern region. the moulouya,one of the main rivers of morocco,through several cities in particular: missour,outat el haj,tindit,guercif,and finally leading to the mediterranean. since several years,a significant deterioration in the quality of its waters,generated by different releases of pollutant emitted into the river without treatment. these releases result from different domestic,industrial and agricultural activities that know this basin. therefore,the lower moulouya site of our study is threatened by pollution and has a good site for accumulation and storage of metal pollutants. to evaluate the spatiotemporal evolution of the metal contamination of the lower moulouya,water and sediment samples were collected along the lower moulouya and tributaries,as ten stations (s1 to s10),the samples were analyzed for heavy metals: iron (fe),lead (pb),zinc(zn) and cadmium (cd),(city of taourirt). the results of analysis by icp-aes,given to reliefs pollution degree by these toxic metals,as iron is the most abundant element in the waters and sediments of the lower moulouya. lead and zinc have moderate to large values,while all of the samples contains relatively low levels of cadmium. analyses have shown also that the highest values of the studied heavy metals are recorded at the levels of neighboring resorts of human activities and industrial and agricultural units,subject to the contribution of polluted waters.