SEDIMENT TRANSPORT AND RAINFALL EROSIVITY EVOLUTION IN TWELVE BASINS IN CENTRAL AND WESTERN ALGERIA

Abstract

Soil erosion by rain and surface runoff is an important problem in the Mediterranean countries. The study of the relationship between erosion and sediment transport with hydrological and climatic factors have been conducted in many countries around the world. The aim of this work is to show rainfall impact on the variability of spatial and temporal concentration in twelve drainage basins in the west of Algeria. We will also seek to find a representative parameter of rainfall erosive potential on a Time and spatial scale. When studying sediment transport in twelve drainage basins of the Centre and the west of Algeria, we have found that the modified Fournier index Which explains much of the specific degradation compared to the Fournier index. The study of the temporal variability of the annual rainfall series, modified Fournier index and concentration of the precipitation in the year for a series from 1930 to 2007 showed a negative trend of the two variables. The annual rainfall and modified Fournier index have declined by more than 20%. This decline is more significant in inland areas.