Soil loss assessment in the Turbolo catchment (Calabria, Italy)

Soil loss caused by accelerated erosion is a growing problem in the Mediterranean belt in general, and in many parts of the Calabrian region (Southern Italy), in particular. It is due to the combination of peculiar geomorphological, pedological and climatic features, very often exacerbated by unsuitable land management. The aim of this study is to analyze and map soil loss by water-induced soil erosion at the catchment scale. Soil loss was quantified using the revised universal soil loss equation (RUSLE) model implemented in a geographical information system. The RUSLE is an empirical model which estimates the average annual soil loss that would generally result from splash, sheet and rill erosion. The analysis shows that total soil loss estimated in the study area is 16,470.88 t yr−1 with an average annual soil loss of 5.65 t ha−1 yr−1. Spatial variation and rates of soil erosion are mainly linked to land use, and the rate of soil erosion varies from less than 1 t ha−1 yr−1 in wooded areas to more than 40 t ha−1 yr−1 in barren land. In addition, the comparison between soil loss and slope maps shows that ∼47% of the estimated soil loss involves slopes with a gradient >20°. The map shows seven classes of soil loss, with 8% in the upper three classes and 51% in the lowest class.