Estimating Enhanced Fujita Scale Levels Based on Forest Damage Severity
A statistical resampling procedure begins by randomly drawing a small sample of trees from this database of observed trees. The coupled wind and tree resistance model determines the percentage of trees in that sample that fall for a given wind speed increment ranging from light breezes to extreme wind speeds. By repeating this procedure a sufficient number of times, each wind speed increment corresponds with a Gaussian distribution of treefall percentages in the sampled plots. Comparing these results with the observed percentage of downed trees in small subplots along the entire tornado track allows an estimation of the most probable wind speed associated with each subplot. Maps of estimated EF-scale levels reveal the relationship between complex terrain and wind speeds and show the variability of the intensity of each tornado along both tracks. This approach may lead to methods for straightforward estimation of EF-scale categories in remote or inaccessible locations.