GEOG 483: Problem Solving with GIS
Brian G. Buchanan
Project 2: Summarizing and Displaying Property Damage from Tornados
January 20, 2008
Living in Oklahoma, tornados are a fact of life. On May 3, 1999 the largest outbreak of tornados ever recorded in the state lay waste to a large number of counties in the state (King 2007). Approximately 74 tornados were observed across the region, and resulted in the death of 48 people while injuring an additional 795 people (King 2007). The total property damage exceeded one billion dollars. The following maps demonstrate how damaging the storms were by examining: the tornado paths, property damaged, property destroyed (by number), property destroyed (by dollar) and the housing unit density. The maps produced a graphic demonstration of the data (approximated for the purpose of this lesson). In addition, certain generalizations could be made based upon an analysis of the maps.
All of the maps were produced using ArcView 9.2 and were placed within the State Plane Coordinates for Oklahoma using a datum of NAD 83 North FIPS_3501_FEET. The maps were all projected using a Lambert Conformal Conic projection.
Figure 1 shows the state of Oklahoma and the 17 counties affected on May 3rd by the tornados. In addition, this map thematically demonstrates the tornados' paths based upon the Fujita scale, or F-SCALE. The Fujita scale “is determined based on damage observed F0 being the weakest and F5 being the strongest” (King 2007). After I downloaded the data, the initial step was to place the map projection and its associated data into the correct coordinate system, which in this case was using the State Plane Coordinates for Oklahoma based upon NAD 83. After this, I joined the data tables together and exported the data into shapefiles that I then could use as layers on the map.
Figure 1: Map of Oklahoma showing the counties affected by tornados on May 3, 1999 as well as the path of the tornados and their strength on the Fujita scale. Produced using Arview 9.2 on January 20, 2008.
Figure 2 is a thematic map showing the property damaged by the tornados in the 17 counties as well as the paths of the tornados and their strength on the Fujita scale. Notice that the counties with more damage also contain higher numbers of tornados, as well as tornados that rated higher on the Fujita scale.
Figure 2: Map of Oklahoma showing the property damage from the tornados on May 3, 1999. This map was produced using ArcView 9.2 on January 20, 2008.
Figure 3 is a thematic map showing the property destroyed in Oklahoma on May 3, 1999 based upon the total number of properties destroyed. Note that the counties within Figure 3 that contained the higher number of properties destroyed generally corresponds to the counties within Figure 2 containing the most property damage.
Figure 3: Map of Oklahoma showing total destruction of property on May 3, 1999. The map is based upon the total number of properties destroyed in each county. Produced using ArcView 9.2 on January 20, 2008.
Figure 4 is a thematic map showing the property destroyed in Oklahoma on May 3, 1999 based upon the value of the property (in US dollars). Generally, the destruction of property based upon the number of properties destroyed (Figure 3) and the destruction of property based upon their value (Figure 4) correspond with one another.
Figure 4: Map of Oklahoma showing the total destruction of property on May 3, 1999 based upon the value of the property (in US Dollars). Produced using ArcView 9.2 on January 20, 2008.
Figure 5 is a thematic map showing the housing density within the 17 counties affected by the tornados on May 3, 1999. The demographic data is based upon the 2000 census. The density was reached by dividing the area in square miles of each county by the number of housing units within the counties.
Figure 5: Map of the 17 counties within Oklahoma affected by the tornados on May 3, 1999. This map shows the housing density within the counties. Produced using ArcView 9.2 on January 20, 2008.
It is interesting to compare and contrast Figures 2 through 4 with Figure 5. The counties with the highest density also were hit with tornados that rated the highest on the Fujita scale. These counties, roughly located in the center of each Figure, contained the highest amounts of property destroyed and damaged by the tornados. It appears that the greater the housing density, the larger the tornados destructive force (based on the Fujita scale).
By using a GIS, I was able to produce maps showing the paths and the destructive force of the tornados on May 3, 1999 in Oklahoma. In addition, I was able to thematically show the amount of property damage and property destruction in relation to the housing density within the 17 counties affected by the tornados on May 3rd. In doing so, large amounts of data were synthesized to show that when an area with a high housing density is hit by tornados, generally property damage and destruction is higher than an area with less housing.
Source
King, Beth (2007) Problem Solving with GIS, Lesson 1. The Pennsylvania State University World Campus Certificate Program in GIS. Accessed 11 January 2008.
This document is published in fulfillment of an assignment by a student enrolled in an educational program of The Pennsylvania State University. The student, named above, retains all rights to the document.