PROBABILISTIC-BASED HURRICANE RISK ASSESSMENT AND ...

purchase insurance to protect against the potential losses caused by flooding (FEMA2009). After the implementation of the NFIA, flood damage prediction has becomeincreasingly important. Structural damage due to surge is not solely dependent on waterdepth, but factors such as duration, possible contamination, and flood velocity alsocontribute to the level of damage experienced by the structure. Because the lack ofconsistent data available and difficulty in integrating the various factors together, surgedamage is generally related solely to water depth (e.g. Green 2003, Van der Sande et al.2003). As with hurricane wind vulnerability models, hurricane-induced surgevulnerability models involve the development of vulnerability curves, i.e. depth-damagecurves, that plot the level of damage versus the surge height (i.e. water depth). The levelof damage is often expressed as a percentage of the replacement cost of the structure orcomponent of structure. Furthermore, depth-damage curves are often provided separatelyfor components (e.g. structural components and contents). It is assumed that componentbasedvulnerability curves (i.e. providing separate curves for components) are particularlyessential in estimating flood damage as the location of components will significantlyimpact the level of damage experienced.Depth-damage curves have been developed by the U.S. Army Corps of America (USACE1970) and the Flood Insurance Administration (FIA 1970). These damage curves aremost often used to estimate potential damage as a result of flooding. Grigg and Helweg(1975) compared the USACE and FIA damage curves and found that the FIA curves aremore reasonable. The USACE has since improved the FIA damage curves (USACE2000, 2003). FEMA (2003) developed the Residential Substantial Damage Estimator(RSDE) to estimate substantial damage (i.e. more than 50% damage), but this approach ishighly biased to the individual assessing damage. Skinner (2006) found that the depthranges within the RSDE were too broad when the methodology was compared to claimsdata from Hurricane Katrina.Since, FEMA (2006) has developed HAZUS-MH Flood Model to estimate flood losses.The model estimates water depth as a function of the flood frequency, discharge, andground elevation. The HAZUS-MH Flood Model includes over 900 depth-damage curvesto estimate loss to various types of construction (Scawthorn et al. 2006). The model18