Development of a generic concept to analyze the accessibility of emergency facilities in critical road infrastructure for disaster scenarios: exemplary application for the 2017 wildfires in Chile and Portugal

Abstract

Natural hazards such as earthquakes, floods, or wildfires pose a serious threat to road infrastructure. Especially in emergency situations, the society depends on the road infrastructure to maintain its functionality in terms of evacuation and accessibility to emergency facilities. In this paper, we develop a generic, multi-scale concept to analyze the accessibility to emergency facilities in critical road infrastructure for natural disaster scenarios. We follow a modular approach: The basic module evaluates the accessibility of emergency facilities by calculating an accessibility index. Other modules enable the calculation of a grid-based index and the generation of a degraded network based on a natural disaster scenario. OpenStreetMap serves as a free-to-use and worldwide available database for the road network and the emergency facility location. The concept is applied exemplarily for two wildfire scenarios of different geographic scales: the January 2017 Wildfires in the BioBio and Maule region located in central Chile and the June 2017 Wildfires in central Portugal. An impact analysis of the wildfires on the accessibility of emergency facilities is performed and evaluated. As a result, the concept provides a valuable and data-sparse decision aid tool for regional planners and disaster control. It can be used in different stages of the disaster risk management cycle. In the mitigation and preparation phase, places with poor accessibility can be identified. In the short-term response phase after a disaster, the quick identification of critical and disconnected road network parts assists disaster control in planning a possible reaction strategy.