Mapping total suspended matter along Moroccan coast using satellite data series

Abstract

Remote-sensing techniques are a powerful technique for monitoring turbidity over the whole littoral areas. Different sensors can be used to quantify and analyze water quality parameters such as colored dissolved organic matter, total suspended sediments, chlorophyll-a, and pollutants. Therefore, the goal of this paper is to investigate the inter-annual and spatio-temporal variability’s of total suspended matter (TSM) concentration in the water surface layer. The coastal of the Atlantic Ocean, Morocco is taken an application area. The results show that high TSM (18 g m−3) is observed during winter season, and lower TSM (2 g m−3) is observed during summer season. In addition, the relationship between TSM and wind speed; and with ocean current was analyzed, and the results show that: (1) sand dredging areas usually coincide with region that have high TSM levels; (2) the wind and ocean current were both important to TSM variation; (3) the increased level of sand dredging in response to rapid economic growth has deeply influenced the TSM pattern since 2012 due to the resuspension of sediment in some areas. Visual interpretation of location led to the conclusion that the dredging activities were more located on the northern and western Morocco. Time series of MODIS images revealed a significant increase in water turbidity from 2012 onwards on the northern Morocco. Moreover, strong wind events in the northern Sahara can significantly increase the TSM in turbid coastal waters.