Contributors: Laura Rocchio and Julia Barsi
After the violent March 11 Tohoku earthquake and devastating Japanese tsunami, the U.S. Geological Survey (USGS) coordinated a volunteer GIS-based analysis effort as part of the International Charter ‘Space and Major Disasters’. Upon receiving a request for assistance from Japan Aerospace Exploration Agency (JAXA), the USGS activated a volunteer corps for rapid mapping assistance including participants from the Rochester Institute of Technology (RIT).
Nina Raqueno of RIT used Landsat along with other types of data for pre- and post-disaster assessments. “Landsat helped me understand the extent of damage and their relative location to population centers,” Raqueno explained. Using a false-color image composite (Landsat bands 4, 3, 2), Raqueno and her team were able to map areas inundated by residual tsunami floodwaters.
RIT was asked to generate map products for three specific areas: (1) the Fukujima Dai-ichi nuclear power plant region, (2) Hachinohe, a city 400 miles northeast of Tokyo that was severely affected by the tsunami, and (3) the northeastern Kesennuma region which was ravaged by the earthquake, tsunami, and major fires spawned from the disaster. RIT also used Landsat to generate maps of the resultant debris fields.
Japanese officials requested large maps (Adobe PDF files) that could be downloaded and printed on large format printers in Japan. The officials needed maps that could be used on the ground to help relief workers understand which regions had been hardest hit and to prioritize ground-based relief efforts.
The Landsat thermal band was used to determine if any temperature variations existed in the ocean waters off of the Fukujima nuclear power plant; to date, no hotspots have been found. While much of the intricate mapping was done using high-resolution commercial data, the easy access to free Landsat data, its near infrared and thermal bands, and its wide area of coverage made it an important asset to the relief effort.
Hiroshi Murakami of Japan’s Geospatial and Information Authority expressed gratitude for the maps provided by RIT and other contributors. He explained that the web-posted maps covered most of the coastal areas of the Iwate Prefecture affected by the disaster. And, because cloudy weather precluded aerial photographs, the maps played an essential role. Murakami commented that he is “impressed that so much information on the damaged areas becomes available on the web immediately after the earthquake…”
The International Charter ‘Space and Major Disasters’ strives to provide space-based Earth observation data to countries affected by disasters (man-made or natural). Under the direction of Brenda Jones, the Disaster Response Coordinator at the USGS Earth Resources Observation and Science (EROS) Center, image analysis experts around the U.S. were asked to quickly process satellite data into field-ready maps. USGS contributes Landsat data to these efforts and also coordinates commercial contributions of high-resolution data from DigitalGlobe and GeoEye. Data from other federal satellite sensors (NASA’s MODIS, ASTER, and Earth Observing-1 ALI; NOAA’s AVHRR) are also commonly used in such response situations.
+ Japanese Data Resources
+ Japanese Map Products
+ International Charter: Space and Major Disasters
More frequent satellite observations, such as those of the Harmonized Landsat Sentinel-2 (HLS) dataset, are needed to fully capture flood dynamics in regions experiencing short-lived, ephemeral flooding.