Evaluating the Performance of Three Flood Impact Analysis Tools

Abstract

Flood modeling is a critical part of disaster preparedness and mitigation planning, especially in coastal and riverine urban areas prone to storm surge and flash flooding. Accurately predicting flood impacts can help both civilians and government officials prepare and reduce risk in the event of a flooding event. However, there are many free flood analysis tools that vary in effectiveness and accuracy of analysis. One option to determine risk is to look at flood maps to identify areas within flood zones; but this approach does not account for the depth of potential flooding, damage to infrastructure, or other quantifiable metrics. Other solutions, such as HAZUS-MH and FEMA FAST offer a more detailed analysis by considering the cost of building replacement, and the foundation materials used for construction. Elevation, building data, and a simulated flood mirroring flooding impacts of Hurricane Isobel for the city of Baltimore, MD was consistent throughout analysis. Both HAZUS and FAST yielded overestimates, with FAST being more accurate by 83%. Although there is no clear best tool for mitigation planning, FEMA FAST should be the preferred choice for flood risk analysis.