On March 11, 2011, a magnitude 9.0 earthquake struck off the coast of Japan in the Tohoku region, resulting in a tsunami. An estimated 400,000 people were displaced from their homes, with extensive damage to the coastline and nearby urban areas. Additionally, the combined effects of the earthquake and tsunami caused damage to the Fukushima Dai'ichi Nuclear Power Station. As part of the International Charter for Space and Major Disasters, the United States Geological Survey (USGS) coordinated a volunteer effort—comprised of ten organizations—to aid in the response to the disaster. Here, we describe our contribution to produce high-quality maps of damaged areas using commercial and government satellite imaging systems.
We previously used remote sensing for disaster management in the aftermath of 2010 Haitian earthquake.1 In collaboration with industrial partners (ImageCat, Inc. and Kucera International), we deployed a multispectral airborne imaging system, namely the Wildfire Airborne Sensor Platform (WASP). Our WASP system collected high-resolution visible (i.e., red, green, and blue) imagery as well as thermal IR images in the short-, mid-, and long-wave IR bands. Though designed to aid in wildfire mapping, we flew WASP over damaged areas of Haiti for seven days shortly after the earthquake. We covered over 250 square miles of land and gave the resulting images to the disaster response community via the Internet. Here, however, the goal was to take satellite imagery and produce map products for use in the field.
Maps showing the extent of the debris field for a portion of the city of Kesennuma, Miyagi, Japan, acquired using GeoEye high-resolution panchromatic imagery on March 13, 2011. The blue line indicates the estimated extent of the debris field. Larger images can be downloaded from the Internet.5
The USGS assigned us two regions for analysis along the Japanese coast, the cities of Hachinohe and Kesennuma.2 Our team—composed of faculty, staff, and graduate students—worked on various tasks, including data acquisition and pre-processing, visual analysis and further processing, and final product creation and dissemination. We acquired both panchromatic (i.e., black and white) and multispectral high-resolution images using commercial satellites over our assigned areas. The Japanese government required printable, large-format maps of the affected areas that highlighted regions of destruction and, where possible, the ‘inundation line’ (i.e., the extent the tsunami moved inshore). Where available, we used before and after imagery to provide visual change-pairs for additional context for the relief workers. After acquisition of images and development of the information product, we created maps of the areas. These were generally produced in the Universal Transverse Mercator coordinate system and were scaled to be printable on large-format printers in the field. We submitted all maps to the USGS for a quality check before they were uploaded to a product distribution website accessible to the relief workers in the field.
We used various techniques to develop the information products included in the maps. We used the commercially available, space-based Worldview-2 sensor (DigitalGlobe)3 to collect images in eight spectral bands from the visible to the near infrared (NIR). Fortunately, there were pre-earthquake (January 16, 2011) Worldview-2 multispectral images of Hachinohe, the lesser damaged of the two sites. We obtained post-earthquake images on March 14, 2011. We then produced a large-area map using the NIR band to highlight vegetation and water-affected areas. These spectral bands were used because water and water-inundated vegetation appear particularly dark and were thus useful in establishing which areas were inundated. The damage in this case, while extensive, was found to be largely confined to the near-shore region. Additional visual inspection found that the major bridges and roadways appeared intact.
We next produced a NIR image-derived map covering Kesennuma. We again collected the imagery using Worldview-2 on March 13, 2011, two days after the earthquake. In this case, the damage was extensive and ranged further inland. Flooded areas were still visible, particularly in the NIR bands. By visual inspection we found sediment runoff in the ocean as well as damage to bridges and other infrastructure. Consequently, we acquired a post-earthquake GeoEye4 panchromatic image of Kesennuma. Panchromatic images typically have higher spatial resolution than color images, thus enabling accurate isolation of spatial features. Our image covered the city and much of the surrounding area. Visual inspection was used to delineate the extent of the debris field. We converted this into a shape file and eight maps were created (see Figure 1). Each map displayed the large-area image—with the debris field extent identified—as well as a close-up image of the region of interest.
After completing the analysis of the Hachinohe region, we were assigned the task of producing high-resolution imagery products over the Fukushima Dai'ichi Nuclear Power Station. These were required to aid in the damage assessment at the plant. Fortunately, Worldview-2 high-resolution panchromatic images were available from March 12, 2011, after the earthquake and tsunami, but before the explosions at the power station. We then collected a second Worldview-2 image over the area on March 17, 2011, after three of the reactor buildings had suffered damage. The before and after images were combined into a high-resolution map and distributed to relief workers on the evening of March 18, 2011, within 24h of image collection. On March 19, 2011, we acquired a GeoEye panchromatic image collected from a slightly different observation angle. Using this, we produced an image pair showing the nuclear plant from both perspectives, providing better context for the extent of the damage to the facility. We also produced additional maps outlining damage to the region surrounding the power plant.
In all, we delivered 15 image-derived map products to the relief workers in Japan through this collaborative effort with the USGS. Our combined efforts demonstrate the utility of high-resolution imagery in disaster response, and highlight the need for temporally relevant information products to first responders on the ground. We continue to provide support to the disaster response community in the event of future response efforts.
The authors wish to acknowledge the United States Geological Survey for their participation in this effort.
David Messinger, Don McKeown, Nina Raqueño
Chester F. Carlson Center for Imaging Science
Rochester Institute of Technology
David Messinger received his bachelors degree in physics from Clarkson University, Potsdam, New York and his PhD in physics from Rensselaer Polytechnic Institute, Troy, New York. He is currently an associate research professor and director of the Digital Imaging and Remote Sensing Laboratory.
1. David W. Messinger, J. van Aardt, D. McKeown, May Casterline, Jason Faulring, N. Raqueño, Bill Basener, Miguel Velez-Reyes, High Resolution and LIDAR Imaging Support to the Haiti Earthquake Relief Effort, Proc. SPIE
7812, pp. 78120L, 2010. doi:10.1117/12.862090
2. David W. Messinger, Don McKeown, Nina Raqueño, Production of imagery-derived maps to aid the Japanese earthquake/tsunami relief effort, Proc. SPIE 8158, 2011. In press.