Suspended Sediments in the Upper Sebou Watershed

Sediment transport in wadis is a major global problem due to its impact on the degradation of agricultural soils and the silting of reservoirs. In Morocco, although research on this topic is limited, the studies conducted highlight the significant volume of material transported annually by rivers. The Upper Sebou watershed, located between latitudes 33° and 34° N and longitudes 4°03' and 5°20' W, is situated within the northern Middle Atlas Mountains. The Allal Fassi Dam is located in its downstream section, and the watershed covers an area of 5,709 km². Sediments transported in suspension by the river were monitored over the course of one hydrological cycle. The results of this study highlight the unique characteristics of this watershed in terms of the fluxes and nature of the sediments delivered to the monitoring station. The total annual sediment load is, in fact, very moderate compared to the sediment volumes reported for other basins in Morocco and throughout the Maghreb. The study seeks to determine the causes of this low erosion and to explain the seasonal variations in the volume of sediment delivered to the dam and the variation in its composition.