Hurricane Tree Damage and Repair

ABSTRACT During a moderate to severe hurricane more than 5% of trees snap or uproot, depending on the strength and duration of the storm, causing considerable damage to nearby property, housing, and power lines. This study aims to specify the mechanics of trunk damage and possible repair mechanisms. Field data are assembled from trees after hurricane damage to the trunk. Allometric scaling parameters based on trunk diameter (D ^ exp) are determined for the damaged trees’ height, weight, Safety Factor S.F. and critical wind velocity Vcrit. 55% snap via stress fracture of the trunk, 45% by uprooting of the entire tree. Hurricane boundary layer profiles, shear layer forces, Safety Factor (SF), and critical wind velocity Vcrit are determined. Power law exponents (D ^ exp) predict tree height (0.84), weight (2.68), Safety Factor S.F. (0.74), and critical wind velocity Vcrit (0.33) in terms of trunk diameter, with correlation coefficients r = 0.94 to 0.99. Critical velocity Vcrit (wind velocity above which the tree will fail) is found to scale as the Safety Factor S.F.^ (1/2). In conclusion, strategic use of clamps, bolts, tree sap and cables allows restoration of uprooted or snapped trunks for some hurricane damaged trees. Success rate for repair is 67%, average longevity after repair 5.6 years for medium-sized commercially valuable trees.