Quantitative approach to water erosion at different spatial scales: basin of Oued Mina

The complex phenomenon of water erosion in river basins is examined. The ap proach adopted aimed to (a) quantify erosion at several spatial scales, usi ng the Wischmeier method, rainfall simulation over 1 and 87 m(2) plots, exp erimental basins, small darns and a reservoir, and (b) to seek the regressi on model which best explains the relationship between sediment transport an d flow rates for the different forms of erosion. The marl zone, which is th e main source of sediment for the reservoir and represents a fifth of the t otal area of the Mina basin in Algeria, was the experimental area. The resu lts show that, considering the complexity of the factors, it is impossible to extrapolate at different scales. The power model characterizes the relat ionship between sediment transport and flow rates, whatever the spatial sca le considered.