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26 mars 2014
- handle: 10670/1.396f14
- hal: hal-01108495
Mots-clés
Land use change (LUC) Geographical information systems (GIS) Sediment pollution Risk assessmentSujets proches
Land Land utilization Utilization of land Use of landCiter ce document
Mehdi Maanan et al., « A long-term record of land use change impacts on sediments in Oualidia lagoon, Morocco », HAL-SHS : géographie, ID : 10670/1.396f14
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Résumé
An integrated approach, involving land use patterns and heavy metal contents of the surficial and cored sediment,was proposed to detect the characteristic spatial and temporal scale of point and non-point source humandisturbances on the Oualidia lagoon in Morocco. Identification and description of the temporal and spatialdistributions of the main contamination sources of heavy metals are analyzed using statistics and GIS methods.The results show that surficial sediments are highly enriched in heavy metals compared to their preindustrialbackground levels. Land-use types affected lagoon sediment pollution in different ways: 1) agricultural areas hadthe highest potential for sediment contamination by heavy metals, particularly Pb, Cu and Hg, 2) Ni and Cr are themain pollutants originating from urban sewage and 3) oyster farming and traditional land uses such as salt flats,pastures showed low levels of others metals. The enrichment factors (normalized by Al) obtained from thesediment cores indicated that the lagoon is (strongly/moderately) polluted by all metals which were attributed toagricultural activities and wastewater discharges from urbanized areas.