"The Hazus Flood Model produces loss estimates for vulnerability assessments and plans for flood risk mitigation, emergency preparedness, and response and recovery. The methodology deals with nearly all aspects of the built environment, and a wide range of losses. The user can evaluate losses from a single flood event, or for a range of flood events allowing for annualized estimates of damages. Using the extensive national databases that are embedded in Hazus, users can make general loss estimates for a region. These databases contain information such as demographic aspects of the population in a study region, square footage for different occupancies of buildings, and numbers and locations of bridges. The Hazus methodology and software are flexible enough so that locally developed inventories and other data that more accurately reflect the local environment can be substituted, resulting in improved loss estimates. The methods within the Hazus Flood Model are commonly used by federal, state, and local agencies for planning studies and are considered 'reasonable.' Uncertainties are inherent in any loss estimation methodology. They arise in part from incomplete scientific knowledge concerning floods and their effects upon buildings and facilities. They also result from the approximations that are necessary for comprehensive analyses. Factors such as incomplete or inaccurate inventories of the built environment, demographics and economic parameters can result in a range of uncertainty of two or more in loss estimates produced by the Hazus Flood Model."
United States. Federal Emergency Management Agency: http://www.fema.gov/