CONTRIBUTION A L’ETUDE DU TRANSPORT SOLIDE EN ALGERIE DU NORD

Abstract

Nowadays, erosion phenomenon is becoming increasingly important in the Algerian catchment basins. Hydric erosion is the most extensive form in the Algerian basins. It depends on the soils resistance and climate aggressivity. Erosion intensity occurs mainly when there are floods, where a significant amount of sediments is being generated by the basins. Erosion, sediment transport and sedimentation are the cause of the degradation of agricultural soils, siltation of dams and damaged substructures the costs are considerable. In Algeria, for instance, the hydro technical-structures development studies come up against the problem of the lack of data relevant to sediment transport in order to assess its importance. This leads the engineer to use the rule-of-thumb techniques currently in existence for assessing the solid quantities transported annually by water courses during sizing designs. For this, we considered necessary to improve our previous relation along with new data in order to calculate the sediment transport, on annual scale, based on three parameters available at at all catchment basins controlled by hydrometric stations, i.e., run-off, pluviometry and surface area. To give more meaning to the model, we used data from 67 Algerian stations and dams. After using the data of 53 measuring sites for calibrating the model, the validation was performed by taking 14 stations into account. The model reliability was done using Nash criterion. For linearity purposes of the relation, the variables were subject to logarithmic transformation. All Correlation coefficients are significant at the 95% threshold along with a determination coefficient equal to 0,77%. The Nash criterion for model calibration and validation is 77% and 88% respectively.