Road network accessibility assessment during flood events by using infrastructure facility-based indices

The increase in flood events due to climate change leads to significant loss of connectivity and heightens the vulnerability of several areas, disrupting infrastructure and isolating communities. Therefore, there is a need for methods and tools to assess accessibility and enable timely action to mitigate the impacts. This research aims to develop a model to assess accessibility to infrastructure facilities during flood scenarios of varying severity, using data from hydrological models, road networks, and Geographic Information System (GIS) analysis. The model evaluates three infrastructure facilities types: resources (e.g., pharmacies), equipment (e.g., fire departments), and health facilities (e.g., hospitals), by developing and using two indices to support local decision-making during floods. The method is applied in the transboundary Axios River at north Greece. The results highlight significant accessibility reduction to infrastructure facilities at different spatial levels and particularly in specific settlements and municipalities under moderate to extreme flood events.