May 23 - July 29
The Impact of a Violent Tornado in Norman, Oklahoma
Karen Michelle Montes Berríos, Ashton Robinson Cook, Amber Cannon, Somer Erickson, and Mark Shafer
What is already known:
- Previous studies with geographic information systems (GIS) have estimated natural hazards’ impacts in metropolitan areas, like in Chicago and Dallas-Fort Worth.
- Oklahoma City and Moore have had a history of tornadoes in its metropolitan area, but some communities have not.
- GIS analyses can help emergency management officials, meteorologists, and sustainability researchers to effectively prepare for and respond to a disaster because they incorporate infrastructure and land use information.
What this study adds:
- This study analyzes the impact of an 1.07 mile wide EF4 tornado path through central Norman, Oklahoma.
- Damage to residential areas were calculated using Z Estimates, and showed a potential cost of over $1B.
- Evaluation of key locations throughout the tornado track, evaluating their sustainability and vulnerability according to its position.
Abstract:
Several previous studies have estimated impacts from significant tornadoes in large metropolitan areas like Chicago and Dallas-Fort Worth. Such a study has not been completed for the Oklahoma City/Norman, Oklahoma areas, despite their residence in one of the most tornado- prone areas in the world. Norman has had several close calls with violent tornadoes in recent years, including the May 24, 2011 Chickasha-Newcastle and Dibble-Goldsby EF4 tornadoes, the May 20, 2010 Little Axe tornado, the May 19, 2013 Shawnee/Bethel Acres EF4 tornado, and the May 20, 2013 Moore EF5 tornado. Norman has been rather fortunate with regard to significant tornadoes, which have largely avoided the most densely populated areas of the city.
The current study investigates the potential of a violent tornado impacting the most densely populated areas of the city of Norman. In order to evaluate this impact, a simulated tornado track was created by transposing the May 24, 2011 Chickasha-Newcastle EF4 tornado track into the most populated areas of Norman using ArcGIS software. GIS datasets provided by state and local governments, including the locations of buildings within Norman, were analyzed to assess specific impacts on critical infrastructure, commercial, and private residences.
Results from this study indicate that totals from structures impacted directly by this tornado have a cumulative value of approximately $800 million. This figure does not incorporate other peripheral losses (i.e., from vehicles, power poles/street markers, or contents of homes) nor does it incorporate damage at businesses/commercial infrastructure. Additionally, five city government buildings were directly impacted: as well as nine schools and the main hospital in the city. Several major highways in Norman are also included in the damage path, with likely traffic jams on these roads similar to past tornado events occurring in the region. 8,186 buildings were affected by the simulated tornado in this study, which is nearly double the number of buildings impacted in the May 20, 2013 Moore, Oklahoma tornado, where 4,253 buildings were damaged. It is conceivable that losses in Norman could easily exceed the $2 billion of damages that occurred in the Moore tornado, suggesting a potential worst-case scenario for the region.