Case Study 7.1: How OpenStreetMap Used Humans and Machines to Map Affected Areas After Typhoon Haiyan Dan Stowell is a computer scientist who specializes in audio analysis. He is also a regular contributor to OpenStreetMap and participates in the Humanitarian OpenStreetMap Team, an initiative that designs digital maps, deploys field workers and creates custom software for disaster risk reduction. He has a background in open-source software development and machine learning, and is currently a researcher at Queen Mary University of London’s Centre for Digital Music. His website can be found here1. OpenStreetMap is a map database, built on the crowd-edited and copyleft model that many will recognize from Wikipedia. It provides some of the most detailed maps publicly available - particularly for many developing countries. When Typhoon Haiyan struck the Philippines in 2013, a group of volunteer mappers came together to map and validate the damage experienced in the area. This was coordinated by the Humanitarian OpenStreetMap Team (HOT), which responds to humanitarian incidents by “activating” volunteers to map affected areas with fast turnaround. The work combines human validation with automated analysis to get results that are relied on by the Red Cross, Médecins Sans Frontières and others to guide their teams on the ground. The HOT maintains a network of volunteers coordinated via a mailing list and other routes. Twenty-four hours before the typhoon struck, members discussed the areas likely to be hit and assessed the quality of existing data, preparing for a rapid response. Once the typhoon reached the Philippines and was confirmed as a humanitarian incident, the HOT team called for the network of volunteers to contribute to mapping the area, including specific mapping priorities requested by aid agencies. There were two main goals. The first was to provide a detailed general basemap of populated areas and roads. The second was to provide a picture of what things looked like on the ground, postdisaster. Where had buildings been damaged or destroyed? Which bridges were down? Work was coordinated and prioritized through the HOT Tasking Manager website (pictured below), which is a microtasking platform for map-making. It allows HOT administrators to 83