An Unmanned Aerial Vehicle (UAV) Site Investigation of the 29 April 2017 Canton, Texas, Tornado

Unmanned Aerial Vehicles (UAVs) can be an invaluable tool in damage surveys. Benefits of this technology include their ability to access remote or impassable areas, identify unknown damages, and assist with more detailed site investigations and rescue efforts. These images can be used to create 3D environments to better interpret and delineate damages from large areas that would have been difficult in ground surveys. This research examines the effectiveness of UAVs in detecting rural portions and associated impacts of the April 29, 2017 Canton, Texas tornado. In this study, UAVs equipped with a conventional and custom Normalized Difference Vegetation Index (NDVI) camera were deployed to collect videography, high-resolution imagery, and multi-spectral imagery. NDVI analysis is particularly useful to analyze vegetation health and damages which otherwise would not be seen from a conventional camera or ground surveys. Results of imagery analysis show previously unseen damages and quantify impacts at a fine scale. These analyses allowed for a more accurate track width determination with the creation of 3D digital track swaths and multispectral overlays. These findings demonstrate how effective the use of UAVs can be for rapid response storm damage assessments, the high quality of data they can achieve, and how they can help us better visualize tornado site investigations. Such methodology and results can be valuable in meteorological verification as well as adapted to assist emergency management services, property owners, structural engineers, and insurance industry in recovery efforts.