Geologically Active – Williams et al. (eds) © 2010 Taylor & Francis Group, London, ISBN 978-0-415-60034-7 1311 Erosion hazard assessment in “Natura” regions affected by wildfires: A case from Peloponnese, Greece H. Saroglou, V. Marinos, G. Tsiambaos & P. Marinos Department of Geotechnical Engineering, School of Civil Engineering, National Technical University of Athens, Athens, Greece E. Lykoudi Department of Geological Sciences, School of Mining & Metallurgical Engineering, National Technical University of Athens, Athens, Greece D. Zarris Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, Athens, Greece ABSTRACT: The assessment for potential erosion phenomena in the regions protected by the “Natura” network in Peloponnese, Greece that have been affected by the extended fires of 2007 is presented. The methodology to produce ground erosion maps is based on the assessment of: a) geology and hydrogeology, b) geomorphology and hydrographic network, c) hydrology, d) pedology, vegetation and land-use according to the empirical model of the Universal Soil Loss Equation (USLE). In this context an erosion susceptibility classification is applied, concerning the potential of a geological formation to produce loose material, which takes into account: a) the presence, nature and thickness of soil cover or weathered mantle, b) outcrops and lithology of bedrock, c) strength of bedrock or cohesion of soil cover or weathered mantle, d) infiltration and permeability. The erosion vulnerability map from this classification is assessed in combination with the soil loss map produced using the USLE model. 1 INTRODUCTION 1.1 General The forest fires of 2007 have been described as the most catastrophic of the past decades in a European context. The total surface of the burned areas exceeded 2.5 million square km, 301,320 of which belong to the protected areas of the “Natura” 2000 network. It is the first time that the fires have extended far beyond forests and agricultural harvests and impacted seriously villages and infrastructure. The 2007 fires resulted in a human tragedy with 67 fatal- ities and thousands of homeless people. 1.2 Natura regions affected by the 2007 wildfires The location of the protected areas and the extent of the wildfires in the Peloponnesian peninsula are shown in Figure 1. The total surface of the main Natura protected areas in Peloponnese, as well as the percentage of each area that is affected, is given in Table 1. It is obvious that the extent of the environmental disaster, in terms of disaster of the flora and fauna, is immense with numerous effects on the human activities of these regions (e.g. agricultural and socio-economic). Additionally, the wildfire-affected areas became totally unprotected against soil erosion and flooding due to denudation. Therefore it is