Evaluation of soil erosion process of the Tusciano river basin

The application of the RUSLE method allowed to draw up the erosion map of the Tusciano river basin. The map highlights the most vulnerable areas interested by soil erosion and also gives an estimate of the maximum soil erosion. Obviously the average quantity of eroded soil obtained (57 t/ha per year ) must be considered as an approximate estimate, considering the discussed deficiency of some data and the absolute absence of sediment transport capacity data for Tusciano river basin. The availability of in situ measurements, would be naturally useful in order to calculate the SDR, that is the relationship between the rate of eroded material (gross erosion) and the rate that effectively reaches the catchment outlet (net erosion). SDR also influences the eventual pollution of receiving water bodies. In fact, fine-grained sediments transported by surface currents entrain chemical substances used in agriculture, polluting water resources. The analysis of the erosion map of the Tusciano river basin concurred to characterize the hilly areas of the basin as being particularly vulnerable, and therefore provided useful indications for the planning of eventual mitigating interventions on erosion processes. Obviously, the use of antierosive and conservation practices will have to be based on preventive feasibility studies, estimating costs and benefits involved, in order to choose the most suitable actions. However, it should be emphasized that good results can be obtained using simple agronomical practices that enable the reduction of potential erosion risks at low costs. In conclusion, the study suggests that an empirical model as the RUSLE, combined with a multidisciplinary study for an adequate evaluation of the factors and supported by an efficient GIS software, may be used as a reliable predictive tool of erosion risk for hydrographical catchments and an useful support in decision-making processes related to risk assessment and mitigation.