Tornadogenesis and Topography

Indiana, United States

Hsing-O Chiang

There are approximately 1,000 tornadoes annually, with more than 80 percent occuring in the United States and the vast majority in the Great Plains—a region of 20,000 cities and a population of 45,461,286 people. Although they last only seconds or minutes, tornadoes are natural disasters that cause massive destruction.

The first step of this project is to understand the forces at play in the formation of tornadoes and the paths, speeds, and conditions that induce them, and the second step is to propose a speculative scenario on mitigating strategies.

Between 1950 and 2014, 1,393 tornadoes struck Indianapolis. Due to this vulnerability, Indianapolis provides a prime site and prototype. Different topographic forms—depression, plains, hills, cliffs, etc.—with varying surface roughness created by vegetation, trees, sand, and boulders would ultimately allow the terrain to play an active role in the reduction of the devastating power of tornadoes.

Modifications to the one mile by one mile grid system of the suburbs surrounding Indianapolis can weaken and redirect the path of tornadoes away from the metropolitan area.

Top: Section of wind, traveling at different speeds, spinning along a horizontal axis from Canada. Very cold air is located in the middle levels of the atmosphere.