Confronto tra tecniche di misura della produzione di sedimenti in un bacino forestato

In this paper, using rainfall and sediment yield data monitored in a small calabrian basin forested with Eucalyptus trees and the caesium-137 technique, an estimate criterion of the mean annual value of the basin net soil erosion is proposed.For applying this criterion the caesium-137 activity was measured on 55 soil samples sampled in the basin and different 137CS activity profile were applied. The results obtained using the mass balance model as caIibration method of the caesium-137 activity into net soil erosion were compared with the mean annual value of the basin sediment yield monitored in the period 1978-1994. The reliability of the proposed criterion is verified applying five different methods for estimating the mean annual value of the net soil erosion. The analysis showed that the best agreement between the mean annuaI value of basin sediment yield and net soil erosion is obtained taking into account the transport efficiency along the hillslopes, the true input fallout distribution in the period 1959-1970 and an exponential equation for the depth-caesium137 activity profile.