Soil erosion risk, Sicilian Region (1:250,000 scale)

Assessing the risk of soil erosion caused by water at the regional level is important for current and future planning of land use and environmental actions to combat land degradation. The gravity of the risk depends not only on the rate of soil erosion by water, but also on other factors, primarily soil depth and workability of the underlying rocks and sediments, which may be used to calculate the eroded soil. We estimate the rate of erosion by water (tons ha−1 year−1) applying the Universal Soil Loss Equation model. The map of soil content (tons ha−1) to the effective rooting depth was divided by the map of soil erosion rate to obtain the risk of erosion by water in Sicily, expressed in terms of years of complete loss of soil cover. This map was intersected with a map of workability of the underlying bedrock to give advice on where the cost of soil recovery by deep ripping and rock grinding are very high. 8382.9 km2 (32.6% of the Sicilian territory) were rated as at high or very high risk (<100 years), of which 1230.9 km2 developed on bedrock with low workability and so very costly to be recovered.