Impact de l'aménagement hydraulique sur la qualité des eaux et des sédiments de l'estuaire du Loukkos (côte atlantique, Maroc)

The spatial-temporal variations of some physical and chemical parameters (air and water temperature, pH, salinity, dissolved oxygen and conductivity) and the trace metal content in sediments (Fe, Zn, Cu, Cr and Pb) have been studied in the Loukkos estuary in 2006 in relation to wastewater discharges of industrial, agricultural and domestic origin. The results show that, at the site where flow discharges of wastewater from the city of Larache, an increase in conductivity, dissolved oxygen and a slight increase in the pH of the water were observed. Salinity remains relatively high in the estuary and does not undergo a significant decrease excepting during the periods when waters are released from dams, causing an overflow the protection dam. The metallic content remains relatively low except for chromium, which reached high levels near the main collector located upstream of the estuary. Globally, these results show that the content of these metallic elements, compared with other estuaries in Morocco, is within the acceptable standards and levels of reference.