Evaluating Landslides’ triggering precipitation thresholds, in regions affected by wildfires, using public and open access data. The case of North Peloponnese, Greece

Abstract

Wildfires pose nowadays a serious threat for human societies as they significantly change the local environment and cause many fatalities around the world. Besides their direct catastrophic results on local ecosystems, they can also be responsible for the acceleration of other devastating phenomena, such as the landslides. This threat is rather critical for the Mediterranean area, where the number of the wildfires is expected to be significantly increased in the following decades, due to climate change. During this study, the impact of the wildfires, on the landslides’ activating mechanism is examined and analysed, through the evaluation of the trend of the landslides’ precipitation thresholds before and after the wildfire events occurred in North Peloponnese Greece, in 2000 and 2007. The determination of these thresholds in a local scale, is a rather critical process for the effectiveness of early warning systems, that can be applied in case of a potential landslide’s activation, to the nearby cities. As, it is revealed, the relevant intensity – duration (ID) precipitation thresholds in the study area, have been declined after some wildfire events, showing that the vulnerability of the area to landslides, has been relatively increased. Thus, the evaluation of the landslides’ precipitation thresholds emerges as a dynamic process and the need for an urgent thresholds’ update after a wildfire event, is highlighted. In that direction the followed process, was conducted by using public data or open access data. Thus, the applicability of these open access tools and platforms, after a wildfire, on the regular and direct update of these thresholds is underlined.