Analyzing the Effect of Open Street Map During Crises: The Great East Japan Earthquake

This paper shows that OpenStreetMap (OSM) played a useful role during the Great East Japan Earthquake of 2011. OSM, which provides free geographical information, is sometimes referred to as a map version of Wikipedia. Its data additions, updates, and corrections are made available by its participants. We compare the data before and after the Great East Japan Earthquake and analyze the transitions. An increase in the amount of OSM editing was observed just after the earthquake. For example, the distance of roads was about six times greater and the area of buildings was approximately five times larger. The number of edited satellite photos nearly doubled. Data collection was carried out in OSM as soon as possible after the earthquake.