Identifying elements at risk from OpenStreetMap: The case of flooding

The identification of elements at risk is an essential part in hazard risk assessment. Especially for recurring natural hazards like floods, an updated database with information about elements exposed to such hazards is fundamental to support crisis preparedness and response activities. However, acquiring and maintaining an up-to-date database with elements at risk requires both detailed local and hazard-specific knowledge, being often a challenge for local communities and risk management bodies. We present a new approach for leveraging Volunteered Geographic Information to identify elements at risk from the free and open-source mapping project OpenStreetMap. We present initial results from a case study in the city of Cologne, Germany, to validate our approach in the case of floodhazard. Our results show that the identification of elements at flood risk from OpenStreetMap is a suitable and costeffective alternative for supporting local governments and communities in risk assessment and emergency planning.