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Natural disasters claim thousands of lives annually, ripping apart communities and demolishing entire infrastructures. In the United States alone in 2003, there were 438 weather-related fatalities, nearly 3,000 injuries and $11.4 billion in damages. Although the effects of natural disasters on human lives aren’t easily mitigated, there are some effective solutions to the problems of disaster planning, prevention, and response and recovery initiatives.


One provider of such solutions is Long Beach, Calif.-based ImageCat Inc. (www.imagecatinc.com), which develops innovative approaches to earthquake risk management and post-disaster damage assessment. Supported by grants from the National Science Foundation (www.nsf.gov) and the Multidisciplinary Center for Earthquake Engineering Research (www.mceer.buffalo.edu), ImageCat has pushed the geospatial technology envelope when it comes to analyzing and mitigating risks associated with natural disasters.


Since Earth Imaging Journal brought readers “Earthquake Recovery: QuickBird Imagery of Algeria Supports Damage Detection and Relief Efforts” (Vol. 1, No. 1—online at www.eijournal.com/algeria.asp), ImageCat has custom-built a robust portable notebook-based reconnaissance system that links high-resolution QuickBird satellite imagery from Longmont, Colo.-based DigitalGlobe (www.digitalglobe.com) to a real-time Global Positioning System (GPS) feed. The system, Visualizing Impacts of Earthquakes with Satellites (VIEWS), has been used successfully in the field internationally to investigate damage from recent deadly earthquakes and windstorms.


For several years, ImageCat researchers have investigated how remote sensing technologies can improve response and recovery activities following major earthquakes. The company’s milestone research and development activities now have spiraled into applications that support investigations of other disasters, such as hurricanes.
 

As ImageCat furthers its collaborative work with other organizations dedicated to the same cause, it will no doubt find more ways to integrate satellite imaging technology and multimedia techniques, providing new solutions that improve response and recovery efforts for years to come. Consider the important societal benefits of the VIEWS system in the following case studies from around the globe.
 

 
 

In Dec. 26, 2003, a powerful earthquake with a magnitude of 6.6 on the Richter scale struck southeastern Iran, killing 26,000 people, injuring 20,000 and leaving 60,000 homeless. The earthquake destroyed much of the city of Bam—an estimated 90 percent of the city’s buildings were destroyed or severely damaged, including the old quarter and a 2,000-year-old citadel built primarily of mud brick.

 
For the first time, the Earthquake Engineering Research Institute (www.eeri.org) reconnaissance team was able to use the custom-built VIEWS system to assess urban damage caused by the Bam tremor. With high-resolution QuickBird satellite imagery purchased by the Earthquake Engineering Research Institute and the University of California at Irvine (www.eng.uci.edu), providing citywide coverage, VIEWS let the reconnaissance team visualize damage sustained by individual structures and directed them to the hardest hit areas.


Using before-and-after QuickBird imagery, an automated texture-based change detection algorithm was created, offering a “quick-look” damage assessment and providing the focus for more detailed inspection of building damage using visualization techniques. A visual comparison also was drawn between enlarged views of the QuickBird images collected three months prior to the earthquake and one week after.


The extremely detailed before-and-after images revealed widespread changes to the city. In the building damage map, areas that experienced extreme changes, such as collapsed structures, were indicated in red. Clearly defined dwellings in the “before” image scene were indistinct piles of debris in the “after” image.

 

 

 
 

QuickBird imagery also served as a basemap and orientation device for response teams unfamiliar with Bam. To help users gain and maintain their bearings, VIEWS tracked their current position with a real-time GPS feed. As responders entered data, such as building damage descriptions and photograph ID numbers, the information was linked to their current GPS locations. The system also provided easy recall for observations made in the field. Back in the office, VIEWS datasets were readily transferred to a geographic information system (GIS) environment for further analysis.

 
“The ability to display all the sources of graphical field data—digital satellite images along with video or still photographs—when we were back in the office re-created the environment for us,” explains Charles Huyck, ImageCat’s senior vice president. “Combining these technologies was invaluable for understanding what was happening in the field.”


During the months following the Bam reconnaissance effort, ImageCat further honed its data collection techniques and prepared for another potential deployment.

 

 
 
 
 

Hurricane Charley struck the Florida coast on Aug. 13, 2004. The most severe windstorm to strike the United States since 1992, Hurricane Charley incited President Bush to issue a presidential disaster declaration for 25 counties in the southeastern region of the United States. The Category 4 hurricane resulted in the loss of at least 27 lives, and caused more than $15.4 billion of damage.


After a disaster such as a hurricane, clean-up operations typically are initiated as soon as possible. There is a narrow time window for documenting perishable damage to buildings and infrastructures. The ImageCat team was quickly on the scene with newly collected satellite imagery and the VIEWS system.
 

 
  “The VIEWS program was built specifically around timely satellite imagery,” says Beverley Adams, remote sensing group leader at ImageCat.  “It’s designed for reconnaissance teams to take into the field and start recording on-the-scene information immediately, so the fresh imagery really supported our efforts after Hurricane Charley.”  VIEWS was used to collect perishable damage data on two separate field trips that took place between Aug. 18-21, 2004, and Aug. 24-27, 2004. Efforts focused on the towns of Port Charlotte and Punta Gorda. The response team used QuickBird imagery collected before the hurricane—on March 23, 2004—and in the immediate aftermath—on Aug. 14 and 19, 2004.  
 
   
 
 

For the post-Hurricane Charley assessment, ImageCat acquired funding from the National Science Foundation’s Small Grants for Exploratory Research program, the Natural Hazards Research and Applications Information Center Quick Response program and the Multidisciplinary Center for Earthquake Engineering Research post-disaster field deployment program. The Wind Science and Engineering Research Center at Texas Tech University also accompanied ImageCat on its field reconnaissance trips.


The field trips enabled the analysis team to validate building damage characteristics identified on the satellite imagery. Traditional methods of post-hurricane damage assessment involve walking surveys where damage indicators, such as the failure of roof covers, roof structures and windows and doors, are logged on a spreadsheet.

 
   
“Engineers typically have to manually record what they see on a clipboard,” relates Adams. “This is very time consuming and slows down the data recording process.” By contrast, the ImageCat team was equipped with satellite imaging technology and the VIEWS field reconnaissance system, which substantially accelerated and streamlined data collection.


Combined with a digital camera and digital video recorder technology, VIEWS can be used from either a moving vehicle or on foot during a walking tour. “Our technology-driven approach has increased our efficiency 25-fold,” says Adams. “Traditional survey techniques typically enabled 20 to 100 buildings to be surveyed in one day. Using VIEWS and satellite imagery, our field experts were able to capture damage data for an average of 2,500 buildings per day.” Capturing the data digitally also produced a permanent visual record of damage sustained by individual structures.


Working with the Multidisciplinary Center for Earthquake Engineering Research, ImageCat took its reconnaissance efforts one step further with the development of tandem Internet- and desktop-based virtual reconnaissance systems (VRSs), which enable ImageCat analysts to integrate, share, visualize and analyze post-disaster field data collected using VIEWS. After Hurricane Charley, VRS provided researchers with easy access to the satellite imagery, GPS readings and geo-referenced video and photographic records for Port Charlotte and Punta Gorda. Users can toggle between multitemporal and multisource satellite images, and explore these images in detail using zoom and pan functions. By overlaying the data with GPS routes and selecting a GPS point, users can view corresponding video footage and scroll through the archive of nearby photographs.

 
 
 

 
     
  In earthquake hit Niigata, on the Sea of Japan’s coast, on Oct. 23, 2004. With a magnitude of 6.8, it was the deadliest to hit Japan since the Kobe earthquake killed more than 6,400 people in 1995. The Niigata tremor left 36 dead and more than 85,000 people evacuated or homeless. More than 5,700 homes and 2,887 buildings were damaged; 312 homes were destroyed. Hundreds of aftershocks throughout neighboring regions buckled highways, twisted rail lines, collapsed bridges and triggered landslides.


ImageCat’s Charles Huyck traveled to Niigata with the Earthquake Engineering Research Institute reconnaissance team to record the aftermath of the earthquake. “Because VIEWS can be deployed by car as well as on foot, large swaths of land were rapidly videotaped during that narrow window of time between the devastating event and the onset of clean-up operations,” relates Huyck.


In the georeferenced video taken in the Niigata region, green, yellow or red building tags, indicating building safety, could be cross-referenced with GIS data such as soil or ground motion.

 
“Landslides are one of the biggest worries in the Niigata region, which has been experiencing heavy rainfall since the earthquake,” adds Huyck. “The QuickBird imagery collected afterward provided an excellent view of the extensive landslides in areas that were often inaccessible by land.”

 
     
     
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