Summary

The Historical Damage Assessment Database is a repository of geospatial damage assessments from past National Disaster events where damage assessments were conducted either using high-resolution imagery or by means of geospatial modeling. The purpose of generating geospatial damage assessments is to provide rapid situational awareness of the number of structures impacted.

Methodology

For visual damage assessments using post-event imagery:

Destroyed structures are classified based on a visual post-event imagery review that the structure was collapsed. Affected structures were classified based on a visual post-event imagery review indicating there were missing roof segments, failure of structural elements, and visible damage. Visual imagery assessments are primarily completed using nadir “looking straight down” imagery so damages to the sides of buildings were not included in the visual assessments. Often, imagery was not acquired during peak flood crests on rivers or surge inundation along the coast and as a result, the visual assessments may focus on resulting wind damages, not flood impacts. There may be damages visible on-the-ground that were not assessed using the imagery.

For modeled damage assessments using depth grids:

Damage categories (Affected, Minor, Major, Destroyed) are derived from flood depths at the structure as characterized by the best-available flood depth grid at the time of the damage assessment.

Data Dictionary

Damage Level:

The damage category assigned to the structure based on modeled or visual assessment.

Affected

Minor

Major

Destroyed

Damage Type:

The type of event that created the damage. Multi-event: more than one type of event created damage.

Assessment Type:

The method for assigning a damage category:

Field Assessed: damage category validated in the field

Modeled: damage category predicted based on modeled wind, flood or surge data

Other type: damage category predicted based on other type of geospatial analysis

Remote Sensing: damage category assigned using image processing and image validation

Unknown: damage category predicted based on unknown type of analysis

Inundation Depth:

Depth of flooding in feet. Predicted/modeled or measured/observed.

Wind Exposure Level:

Severity of wind impact the structure experienced based on the Saffir-Simpson Hurricane Wind Scale or the Enhanced Fujita Rating for Tornados.

Peak Ground Acceleration:

PGA experienced by the structure during an earthquake based on USGS ShakeMap GIS data.

Accessible:

Indicates whether the structure is accessible or inaccessible due to debris, flooding, damage or other reason.

Production Date:

Date when the damage category was assigned.

Imagery Date:

Acquisition date of the image that was used to assign structural damage categories.

Event Name:

Name of the natural disaster that caused the damage.

Event Date:

The date of the event or natural disaster.

Data Producer:

Organization that created the damage assessment data.

Disaster Number:

Unique ID value assigned for natural disaster events.

USNG:

The USNG grid ID that the structural damage lies within.

Data Sources

Public Release 4/22/2019:

  • EF4 Tornado Lee County, Alabama (2019)

Public Release 11/26/2018:

  • Hurricane Matthew (2016)

Public Release 11/13/2018:

  • Hurricane Harvey (2017)
  • Hurricane Hermine (2016)
  • Hurricane Irma (2017)
  • Hurricane Isaac (2012)
  • Hurricane Maria (2017)
  • Hurricane Michael (2018)
  • Hurricane Nate (2017)
  • Hurricane Sandy (2012)
  • Joplin Tornado (2011)
  • Louisiana Floods (2016)
  • Oklahoma Severe Storms & Tornadoes (2013)
  • Tuscaloosa-Birmingham Tornado (2011)

Access & Use Information

Public: This dataset is intended for public access and use.

Downloads & Resources

Download

FEMA Geospatial Damage Assessments App

Contact

FEMA Mapping and Analysis Center (MAC)

Disclaimers

Assumptions:

  • The damage assessment point is where the affected building was located.
  • It is unknown which points indicate structures that are elevated above ground level. Some of these structures may have a ground floor that lies above the inundation layer and as a result, sustained damage was not able to be captured accurately.
  • Points were partially modified based on their parcel occupancy type, when available. For example: Parcels with PROP_IND_T = “Vacant” were removed from the analysis and parcels with duplicate APNs were removed. These adjustments might cause extra deletions causing some points over structures to not exist in the dataset.
  • Methodologies used to generate depth grids for flood and surge events do not account for flooding as a result of storm water backups, irrigation ditch failures, flooding from dam or levee breaks, use of spillways and weirs, or resulting wind damages.

User assumes all risk related to the use of this data. FEMA provides this data “as is” and disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose, and there are no express or implied guarantees of accuracy of the data. In no event will FEMA or any other Federal Agency be liable to you or to any third party for any direct, indirect, incidental, consequential, special, or exemplary damages or lost profit resulting from any use or misuse of this data.

References

-->