Erosion risk and desertification risk at Pyrgos, Greece

Abstract

Summertime forest fires are a major problem in all Mediterranean countries and a factor that contributes in erosion and desertification of large areas. During the summer of 1998, the area of Pyrgos (prefecture of ILIAS, Western Peloponnese) suffered from a wild fire. Large areas of vegetation and forest have been destroyed. In ths study, we examine the erosion risk and desertification risk for these areas, taking into consideration the following parameters: Geology, slope gradient, type of vegetation, soil type, soil depth and rainfall. For the best management of the data, we used the GIS technology and the equipment of the Remote Sensing Laboratory. First, we digitized all the available maps of the area at a scale of 1:50000 (1:20000 for the vegetation map). Then, we created the DEM, the slope map and the aspect map of the whole area. For the destroyed areas, we made a classification for the erosion risk, taking into consideration the surface geology, the rainfall erosivity and the percentage of the slope. Then, we made a second classification for the possibility of natural regeneration, taking into consideration the soil type, the soil depth, the aspect class and the vegetation type. Finally, we estimated the desertification risk, as the sum of the classes of the two previous classifications.