Using a flood inundation map library to estimate where floodwaters will go and how deep they will be is crucial for planning and preparing for floods. By performing loss-estimation modeling, the potential physical, economic, and social impacts of disasters can be calculated, helping communities anticipate the effects of flooding and identify specific strategies to reduce losses and speed recovery.
One commonly used loss-estimation model for flooding is HAZUS, which is maintained by the Federal Emergency Management Agency (FEMA). The HAZUS-MH loss-estimation application is a nationally applicable standardized methodology that contains models for estimating potential losses from earthquakes, floods, and hurricanes. HAZUS is used for preparedness and response as well as mitigation and recovery. HAZUS uses GIS (Geographic Information Systems) technology to illustrates the limits of identified high-risk locations and allows users to visualize the spatial relationships between the human populations and assets or resources.
Incorporating HAZUS Information Into the Flood Inundation Mapper
HAZUS-MH is the principal software used to assess flood risk to affected populations, buildings, and other infrastructure in the U.S. However, while HAZUS is able to generate reliable assessments of flood risk, its usefulness is limited because it can only be run on a workstation by a trained operator using ESRI’s ArcGIS software. In 2010, the USGS and FEMA began an effort to solve this problem by integrating HAZUS flood risk analyses with the USGS-produced flood-inundation map libraries and making these data available online.
HAZUS analyses are first run offline for each incremental stream stage (height) over the selected FIM stream reach. For example, a stream reach with inundation maps and depth grids for 15 different stream stage increments would require 15 different HAZUS analyses. Loss estimates are compiled at two scales. The Quick Assessment displays loss estimates for the entire study area, including displaced population, short-term shelter needs, economic property loss, and lost income from business interruptions (fig. 7). The Quick Assessment option also includes regional statistics for the study area, including area, number of Census Blocks, number of buildings (residential and total), population, and total value of exposed buildings. Both Quick Assessment and Loss by Census Block data are calculated for each stream stage increments and uploaded to the USGS Flood Inundation Mapper.
Alternatively, the Loss by Census Block HAZUS feature gives more detailed loss estimates for each census block in the study area. Drop down menus allow the user to select from over 90 different types of damage and loss categories. Census blocks are colored to represent representative values for each stage interval (fig 8).
Visit FEMA's website to learn more about the HAZUS-MH loss-estimation application.
Related science associated with the Flood Inundation Mapping (FIM) Program.
Flood Inundation Mapping (FIM) Program
Flood Inundation Mapping Toolbox
Flood Inundation Map (FIM) Libraries
Emerging Flood Inundation Mapping Technologies
Flood Inundation Mapping Science
Multimedia items associated with flood loss estimation.
- Overview
Using a flood inundation map library to estimate where floodwaters will go and how deep they will be is crucial for planning and preparing for floods. By performing loss-estimation modeling, the potential physical, economic, and social impacts of disasters can be calculated, helping communities anticipate the effects of flooding and identify specific strategies to reduce losses and speed recovery.
One commonly used loss-estimation model for flooding is HAZUS, which is maintained by the Federal Emergency Management Agency (FEMA). The HAZUS-MH loss-estimation application is a nationally applicable standardized methodology that contains models for estimating potential losses from earthquakes, floods, and hurricanes. HAZUS is used for preparedness and response as well as mitigation and recovery. HAZUS uses GIS (Geographic Information Systems) technology to illustrates the limits of identified high-risk locations and allows users to visualize the spatial relationships between the human populations and assets or resources.
Incorporating HAZUS Information Into the Flood Inundation Mapper
HAZUS-MH is the principal software used to assess flood risk to affected populations, buildings, and other infrastructure in the U.S. However, while HAZUS is able to generate reliable assessments of flood risk, its usefulness is limited because it can only be run on a workstation by a trained operator using ESRI’s ArcGIS software. In 2010, the USGS and FEMA began an effort to solve this problem by integrating HAZUS flood risk analyses with the USGS-produced flood-inundation map libraries and making these data available online.
HAZUS analyses are first run offline for each incremental stream stage (height) over the selected FIM stream reach. For example, a stream reach with inundation maps and depth grids for 15 different stream stage increments would require 15 different HAZUS analyses. Loss estimates are compiled at two scales. The Quick Assessment displays loss estimates for the entire study area, including displaced population, short-term shelter needs, economic property loss, and lost income from business interruptions (fig. 7). The Quick Assessment option also includes regional statistics for the study area, including area, number of Census Blocks, number of buildings (residential and total), population, and total value of exposed buildings. Both Quick Assessment and Loss by Census Block data are calculated for each stream stage increments and uploaded to the USGS Flood Inundation Mapper.
Sources/Usage: Public Domain.Figure 7. The HAZUS Quick Assessment shows loss estimates for the whole reach. As the user moves the flood-depth slider on the left hand side of the window, the loss estimates change in accordance with flood severity. Alternatively, the Loss by Census Block HAZUS feature gives more detailed loss estimates for each census block in the study area. Drop down menus allow the user to select from over 90 different types of damage and loss categories. Census blocks are colored to represent representative values for each stage interval (fig 8).
Sources/Usage: Public Domain.Figure 8. The HAZUS Loss by Census Block maps loss estimates by available census blocks, and shades the polygons according to severity. Users can also use the flood-depth slider to display loss-estimate maps over the range of flood depths. Visit FEMA's website to learn more about the HAZUS-MH loss-estimation application.
- Science
Related science associated with the Flood Inundation Mapping (FIM) Program.
Flood Inundation Mapping (FIM) Program
Floods are the leading cause of natural-disaster losses in the U.S. More than 75 percent of declared Federal disasters are related to floods, and annual flood losses average almost $8 billion with over 90 fatalities per year. Although the amount of fatalities has declined due to improved early warning systems, economic losses continue to rise with increased urbanization in flood-hazard areas.Flood Inundation Mapping Toolbox
The FIM Toolbox contains comprehensive information on the Flood Inundation Mapping program, including how to develop a flood inundation map library. Resources include process documents, scientific and technical requirements, forms and templates, outreach and educational materials, and contact information. The FIM Toolbox is updated as new resources become available.Flood Inundation Map (FIM) Libraries
The Flood Inundation Mapping Program focuses on developing flood inundation map libraries and helping communities pair those libraries with real-time stream data and National Weather Service flood forecasts to form a two-dimensional flood warning system. Together, these products can help communities estimate the extent of a flood and identify at-risk areas and resources in advance of floodwaters...Emerging Flood Inundation Mapping Technologies
The following technologies represent state-of-the-art tools, methodologies, and techniques that the USGS and our partners are researching and testing. Most of these techniques are experimental and not publicly available, but could significantly improve our ability to plan for and respond to flooding events in the future.Flood Inundation Mapping Science
When planning for a flood, there are three key questions that must be answered: What areas will be flooded? How deep will the flood waters get? When will the flood arrive? Historical flooding can help a community anticipate how much impact similar flood events could have, but there are other methods and tools that can provide more accurate and nuanced estimations of a wide variety of flood... - Multimedia
Multimedia items associated with flood loss estimation.