Detection of permanently eroded landsurfaces through multitemporal analysis of Landsat data: a case study from an agricultural area in southern Italy

Soil erosion is a critical environmental degradation problem globally, especially in regions economically dependent on agriculture. Remote sensing proved to be an ideal method for a timely investigation of soil erosion over large areas. The aim of this study was analyzing the spatial distribution of soil erosion-prone landsurfaces in an agricultural area of southern Italy in the period 2009-2018 and investigating the environmental features more favorable in triggering soil erosion processes. The study was carried out by integrating the results of multitemporal analysis of Landsat-5 TM and Landsat-8 OLI imagery, GIS analysis, and geomorphological field survey. Erosion-prone landsurfaces were detected through their typical spectral response. GIS analysis allowed discriminating permanently eroded landsurfaces from areas occasionally affected by soil erosion or morphodynamically stable. Severe soil erosion processes affected more than a half of the study area at least once in the considered period. Permanently eroded landsurfaces accounted for 5.4% of the areas affected by soil erosion processes. Lithological and pedological features of the landsurface controlled the spatial distribution of the eroded areas more than slope angle and aspect. The proposed approach allowed producing reliable maps of the areas affected by soil erosion processes in a relatively short time and at a low cost, which represent a first but fundamental step in land management.