Description of a GIS-based rockfall hazard assessment methodology and its application in mountainous sites

In Western Greece, rockfalls occur every year in residential areas and on public roads, causing considerable societal and economic damage. As a result, rockfall hazard assessment is a necessity and can be a very important tool for scientists, planners, decision makers, and local authorities. In the current study, a GIS-based rockfall hazard assessment methodology is presented as a decision model for preventing rockfall threat in residential areas and public roads. This methodology is based on a specific hazard matrix developed for quantitative evaluation of the rockfall hazard in three stages: inventory, intensity, and hazard. The proposed methodology is applied in two mountainous sites located in Western Greece, Santomeri village and Klokova road passage. The final established rockfall hazard maps for both sites seem to be very accurate, and the methodology can therefore be applied in other areas as well and used as a prevention planning tool against rockfall hazardous events.