Analysis of the evolution of soil erosion classes using multitemporal Landsat imagery

A cartographic method based on satellite images was completed in order to analyse the evolution of soil erosion in areas under humid climate conditions that experience frequent small forest fires. The method uses indicators, recognisable in the images, for the spatial and temporal analysis of the soil erosion status in burnt areas where the vegetation recovers quickly after fires. The continuity of the organic horizon, the surface stoniness and the vegetation cover degradation or regeneration were the indicators of the erosive soil class used in the multitemporal analysis of nine Landsat images. The study area is located in the western sector of the Cantabrian Range (NW Spain). The indicators selected were useful to show clearly the erosive status of the soils. Also, the use of multitemporal satellite image analysis seems to be a suitable method for studying soil erosion evolution in areas prone to forest fire. The application of the proposed method showed that in a study area of 48 857 ha, the soil cover was recovering in 7377 ha owing to the smaller frequency of forest fires, and degrading in 2326 ha.