Sunday, 22 January 2012
The Effects of Topography on Spatial Tornado Distribution
Hall E (New Orleans Convention Center )
Topographical influences have been theorized to play a role in tornadogenesis and tornado intensification. The role of topography on the spatial distribution of tornadoes is assessed through the implementation of geospatial and statistical techniques. A 100-m digital elevation model is used to create slope, aspect, and surface-roughness maps of the study area. Tornado beginning and ending points, and the interpolated paths are used to extract terrain information from the digital elevation model. The angles between tornado paths and topographical aspect are compared to discern whether tornadoes tend to occur along certain types of sloping terrain, relative to the tornado paths (uphill, downhill, etc.). Permutation tests, such as bootstrapping, are used to compare confidence intervals of path-relative aspect angles. Results show whether topography plays a statistically significant role in the spatial distribution of tornadoes.