Remote-Sensing Assessment of Wind Damage

Engineering studies of wind-damaged buildings over the past four decades have helped strengthen the built environment against the effects of severe windstorms by influencing building codes, improving mitigation measures, and identifying life-saving construction practices. Post-windstorm investigations are time- and labor-intensive, however, and critical damage evidence is often lost in cleanup and repair efforts before large damage areas can be surveyed. Digital satellite and aerial imagery offers a means of rapidly preserving critical damage evidence (e.g., roof damage and debris spread) and also enables engineers to see damage conditions in inaccessible areas. A wide range of wind damage states are visible from the exterior of buildings: ranging from minor roof-covering damage to removal of the entire structure from the foundation. Many wind damage states can also be detected from the condition of the roof alone with a high degree of accuracy, and wind damage is therefore subject to detection and assessment using remote-sensing imagery. Significant advances in satellite and aerial remote-sensing image acquisition over the past decade have greatly advanced the possibilities for rapid detection and assessment of damage from windstorms [Womble, 2005]. Such recent and major hurricanes as Charley (2004), Ivan (2004), Katrina (2005), Rita (2005), and Wilma (2005), have been accompanied by an abundance of remote-sensing data. For Hurricane Katrina alone, digital images with various spatial, spectral, and temporal resolutions wereacquired from 21 different platforms