Reservoir sedimentation affects the performance of dams in Algeria from the standpoint of reservoir capacity for storage. Foum El Kherza reservoir near Biskra Town, Algeria, is subject to dredging operation with the intent of recovering 70% of its initial storage capacity of 47 hm3 (million cubic meters). The forecasting of sediment volume trapped in the reservoir is essential to plan the future use of this resource and to sustain irrigation for the palm groves characteristic of the region. However, there are currently no sediment data for predicting sediment inflow based on hydrologic data. Based on earlier study on cumulative sediment rating curve approach using daily inflows, this paper describes an optimization of a cumulative trapped sediment curve for the reservoir based on 44 years of annual water inflows, by using a spreadsheet optimization tool, Microsoft Excel® Solver to calibrate the cumulative sediment load against the cumulative sediment inflow as documented by eight bathymetric surveys since dam construction.

La région semi-aride des Aurès présente une diversité floristique et faunistique indéniable, mais des facteurs climatiques comme anthropiques provoquent une régression du couvert forestier. On y étudie, grâce à des images Landsat, les changements d’occupation du sol entre 1987 et 2001. Des images satellitaires multi-dates sont traitées par la méthode de classification supervisée du maximum de vraisemblance. Les résultats obtenus montrent que le couvert forestier, la végétation clairsemée et les sols font l’objet d’une dégradation très avancée.