Imagery-based wind damage functions

Prediction or estimation of wind damage to individual structures using analytical techniques is time-consuming, costly, and often limited by unknown loading factors and structural resistances. Detailed analysis of all individual structures affected by hurricanes or large tornadoes is typically not feasible. Alternatively, wind damage functions (WDFs) for structural components and/or overall systems based on the observation of damages distributed spatially across a known wind field can serve as a significant tool for the estimation or prediction of wind-induced damages. The intensity and spatial distribution of maximum wind speeds in severe wind storms have historically been unknown, and the collection of area-wide and comprehensive damage data via ground surveys has generally proved impossible. However, it is now possible to construct improved wind damage functions based on high-resolution post-storm imagery by correlating observed damage levels and known wind speeds established through the merger of significant new technological developments, including: portable ruggedized instruments that measure wind speeds in-situ, numerical modeling techniques that produce regional velocity fields from available multi-platform measurements, remote-sensing platforms that facilitate the rapid capture and preservation of damage data, and interpretation techniques that aid in identifying levels of wind damage depicted in these remote-sensing data.