Geospatial information for sustainable food systems

Rapid infrastructure damage assessment after Hurricane Iota in Providencia Island, Colombia

Unprecedented damages have been recorded after Category 5 hurricane Iota passed over Providencia Island, Columbia between the 15th and 16th of November 2020. Communication to the island was lost for at least 20 hours. In order to rapidly coordinate emergency response, remote, geospatial products derived from satellites images nowadays offer a vast potential to assist in the planning of appropriate actions.

An assessment of the impact of Hurricane lota in Providencia Island, Colombia, was performed on November 24th, 2020 using an innovative approach based on open-source data and tools. The maps produced provide 30m spatial resolution proxy information about damages of local settlements. New features, recently made available on FAO’s cloud-based geospatial platform SEPAL and initially introduced to improve forest monitoring and land cover assessments, demonstrated their capability to generate rapidly damage proxy maps for supporting emergency response. 

Based on the all-weather, day- and nighttime independent imaging capabilities of space-borne radar instruments on the Copernicus' Sentinel-1 satellites, severe damages of urban areas have been rapidly mapped. The workflow is based on advanced processing capabilities on the SEPAL platform that now includes the fully automated generation of so-called coherent change detection products. This methodological approach follows a similar methodology developed by the NASA–ARIA team.

The results provide a 30-meter spatial resolution proxy map of infrastructure and urban damage severity. Comparison of the images taken before and after the event allowed for the identification of severe damages such as collapse or submergence of buildings and roads. In the future, improved access to higher resolution and timely satellite image will enable further verification and categorization of the severity. Such information have the potential to support rescue teams to be prepared for obstacles such as damaged or flooded roads and prioritize their actions on the worst affected areas.