Program in GIS

Tornado Activity in Oklahoma on May 3, 1999
Overview

Figure 1: Tornado paths during May 3, 1999 outbreak.

Source:  Brenton White ArcMap Project 2 screen capture.

On May 3, 1999 there were 56 tornados of various intensity in Oklahoma causing considerable damage and killing many people.

• 17 counties had tornados touchdown during the outbreak (see figure 1)

• There were 56 tornados during the outbreak (see figure 2)

  • 29 F0

  • 12 F1

  • 6 F2

  • 6 F3

  • 2 F4

  • 1 F5

• 42 people were killed

• 4796 housing units were damaged (see figure 3)

• 1831 housing units were destroyed (see figure 4)

• Total damage exceeded $97,000,000 (see figure 5)

• The most damaging tornado (F5) hitting the two most densely populated counties (see figure 6 through figure 9).

Tornados Varied from F0 to F5

Figure 2: F Scale of each tornado.

Source:  Brenton White ArcMap Project 2 screen capture.

The 56 tornados varied from F0 (minimal damage) to F5 (complete destruction).

Attributes examined resulting from the tornado outbreak of May 3, 1999

• Property damaged
• Property destroyed (in numbers)
• Property destroyed (in US dollars)
• Housing unit density (by county)

Optional Analysis

• Housing unit density using census tract data

Property Damaged

Figure 3: Damage ranged from 3 units in one county to 3,411 properties in another.

Source:  Brenton White ArcMap Project 2 screen capture.

Total property damaged was determined by adding the number of houses, apartments, and mobile homes damaged during the outbreak for each county.

Properties Destroyed

Figure 4: Units destroyed ranged from 2 in one county to 1,182 in another.

Source:  Brenton White ArcMap Project 2 screen capture.

Total property destroyed was calculated by adding the number of houses, apartments, and mobile homes destroyed.

Properties Destroyed in US Dollars ($)

Figure 5: Total destruction ranges from $54,000 in one county to $83,000,000 in another.

Source:  Brenton White ArcMap Project 2 screen capture.

Total property destroyed in US dollars ($) was calculated by multiplying the total number of units destroyed by the median value of the units.

Housing Unit Density

Figure 6: Housing unit density ranged from 5.43 per square mile to 385.14 per square mile.

Source:  Brenton White ArcMap Project 2 screen capture.

Housing density for the county was calculated by dividing the number of housing units in the county by area of the county.

Optional:  Housing Unit Density Using Census Tract Data

Figure 7: Housing unit density ranged from 0 per square mile to 3,966 per square mile.

Source:  Brenton White ArcMap Project 2 screen capture.

Housing density for the census tracks was calculated by dividing the number of housing units in each census tract by area of the tract.

Optional:  Close Up of Housing Unit Using Census Tract Data

Figure 8: Housing unit density ranged from 0 per square mile to 3,966 per square mile.

Source:  Brenton White ArcMap Project 2 screen capture.

This is a close up of the housing unit density looking at the most populated tracts in the counties impacted by the tornado outbreak.

Optional:  Close Up of Tornado Paths and Housing Unit Using Census Tract Data

Figure 9: Path of most destructive tornado hits highly populated areas.

Source:  Brenton White ArcMap Project 2 screen capture.

A major contributor to the significant damage and deaths during the tornado outbreak can be attributed to the fact that the most destructive tornado (the F5) hit some very highly populated areas.

GEOG 5222: Project 2: Summarizing and Displaying Property Damage from Tornados. April 2004.

Census tract data.  http://www.e-education.psu.edu/courses/geog5222/zips/exp2files.zip.  Accessed 20 April 2004.