Local mitigation strategy (LMS) - Volusia County Government

SECTION 5: HAZARD PROFILESThe Saffir-Simpson Scale categorizes hurricane intensity linearly based upon maximum sustained winds,barometric pressure and storm surge potential, which are combined to estimate potential damage.Categories 3, 4, and 5 are classified “major” hurricanes. Hurricanes within this range comprise only 20percent of total tropical cyclone landfalls, but they account for over 70 percent of the damage in theUnited States. Table 5.5 describes the damage that could be expected for a tropical storm and eachcategory of hurricane. Damage during hurricanes may also result from spawned tornadoes, storm surgeand inland flooding associated with heavy rainfall that usually accompanies these storms.TABLE 5.5: Hurricane Damage ClassificationsSTORMCATEGORYDAMAGELEVELWINDSPEEDDESCRIPTION OF DAMAGESPHOTOEXAMPLETropical Storm MINOR 39-73 mphBreaks twigs and branches off trees, damagessignboards, and windows may break.1 MINIMAL 74-95 mph2 MODERATE 96-110 mph3 EXTENSIVE 111-130 mph4 EXTREME 131-155 mph5 CATASTROPHIC 155+ mphNo real damage to building structures. Damageprimarily to unanchored mobile homes,shrubbery, and trees. Also, some coastal floodingand minor pier damage.Some roofing material, door, and window damage.Considerable damage to vegetation, mobilehomes, etc. Flooding damages piers and smallcraft in unprotected moorings may break theirmoorings.Some structural damage to small residences andutility buildings, with a minor amount ofcurtainwall failures. Mobile homes are destroyed.Flooding near the coast destroys smallerstructures, with larger structures damaged byfloating debris. Terrain may be flooded well inland.More extensive curtainwall failures with somecomplete roof structure failure on smallresidences. Major erosion of beach areas. Terrainmay be flooded well inland.Complete roof failure on many residences andindustrial buildings. Some complete buildingfailures with small utility buildings blown over oraway. Flooding causes major damage to lowerfloors of all structures near the shoreline. Massiveevacuation of residential areas may be required.Sources: National Hurricane Center; Federal Emergency Management Agency,Tropical Storm Photo: FEMA/George Armstrong; Other Photos: PBS&J Photo LibraryVolusia County Multi-jurisdictional Local Mitigation StrategyFebruary 20105:11