Evaluation of land use sustainability in a mediterranean area using a hydrological erosion model: an example from central Italy

In Italy soil management is becoming an important issue especially in areas affected by natural hazards such as soil loss. When serious soil loss process occurs, sustainability of land use is strongly depending on understanding and evaluating the interrelated factors influencing such a process. In the context of. such a complex natural system the quantitative study of processes, such as soil loss, needs appropriate instruments and methods. This research work gives a contribution in assessing soil loss processes by using physically based models. On these statement the hydrological-erosion model WEPP (Water Erosion Prediction Project - USDA) is applied. The model results are calibrated using ground truth as direct observation of sediment yields computed on a sub-catchment basin scale. Two sub-catchments of the Arno River were chosen as test areas located on the western slope of the Montalbano ridge in central Tuscany. Soil erosion have been examined on a hilly area, where Plio-pleistocenic deposits are prevalent. Such sites are representative of lithology, vegetation and climatic conditions of the central Italy Mediterranean areas where agricultural activity (i.e.: vineyards and olive groves) is a relevant economic activity. Since the WEPP model has been calibrated in others environmental condition one of the task of this research work deals also with model validation under specific condition such as the ones present in the test areas. The results obtained shows that week soil physical properties and current soil management appears as the most important factors in soil loss.