Scale and Resolution Considerations in the Application of HAZUS-MH 2.1 to Flood Risk Assessments

This study examines a tool developed by the U. S. FEMA for performing earthquake, hurricane, and flood hazard modeling and damage assessment. The focus of this research was to compare the native flood modeling and damage assessment functionalities of this tool with the May 2010 floods that impacted Davidson County (Nashville), Tennessee. Flood scenarios were created at the county and subcounty levels by using 1 and 1=3 arc-second digital elevation models and 100, 500, and 1,000 year flood return periods. The predicted flood surface area and damage levels were compared to observed flooding and damage from the 2010 floods. At the county level, the software was useful in predicting 87% of flood surface area and in identifying areas of damage, but its predictive value was limited at the subcounty level. These findings indicate that this predictive tool can be used primarily for large, county-level estimations as a screening tool to identify high impact areas that may require further analysis using more advanced hydrologic analysis. (C) 2014 American Society of Civil Engineers.