VISOV volontaires numériques en gestion d'urgence | French-speaking Virtual Operations Support Team #VOST | Social Media in Emergency Management #SMEM

A new methodology to standardize remote assessments of wind disaster damage

Stronger cyclones are likely to become more frequent with climate change. Categorie 5 cyclone Winston severely hit Fiji on Feb 20th. A 30 day state of natural disaster was declared. Ten days later, the death toll is 43 at least, and more than 50,000 persons are still living in evacuation centers, and 120,000 need shelter assistance.

Improving recovery capabilities is part of Disaster Risk Reduction (DRR). Assessing the damage and obtaining accurate and actionable information as quickly as possible is critical. Ziad Al Achkar, Isaac L. Baker and Nathaniel A. Raymond, of the Signal Program on Human Security and Technology at the Harvard Humanitarian Initiative (HHI) published these last days a study that describes a new methodology to standardize remote assessments of wind disaster damage, from satellite, aerial or drone imagery, named the “BAR methodology”, with a foreword by Ray Shirkodai, Executive Director of the Pacific Disaster Center: “Assessing Wind Disaster Damage To Structures”.

This methodology takes into account structure categories visible in the imagery, sorted in “A) Light strength structures (the most vulnerable); B) Medium strength structures (moderately vulnerable); and C) Heavy strength structures (usually the least vulnerable).”

Each structure is also assigned a damage scale, which is as follows: “0 = no visible damage to the structure; 1 = visible partial roof damage; 2 = the roof has suffered significant damage or is completely off, but the walls remain standing; and 3 = the walls and the roofs are down and the structure integrity is completely compromised.”

Remote damage assessments have already been produced by the International Charter Space and Major Disasters (see also UNOSAT), European Union Copernicus emergency management service, and Pacific Disaster Center. Post-Winston satellite imagery is available for OSM mappers for the areas of Ba, Tavua and Rakiraki. Aerial imagery is publicly available for many affected areas, and some of it has already been geo-localized on this map.

The goal of this project is to adapt the BAR methodology to the OpenStreetMap framework, using also information available online from social media, such as geo-localisable photos, and apply it in Fiji, to produce detailed open geodata that will hopefully be useful to the Fijian Government, organizations and people to manage the aftermath of this disaster, and also to experiment and refine this methodology as needed for future disasters.

By Jean-Guilhem Cailton