Left: Landsat 5TM CRI result within Tallapoosa County, Alabama, using two parameters - NDMI, and forest classification type to illustrate bark beetle infestation risk within Tallapoosa County without proximity to tornado path as a factor. Right: Landsat 5TM CRI result within Tallapoosa County, Alabama, using NDMI, forest classification type, and proximity to tornado paths. Red areas indicate high bark beetle susceptibility, orange areas moderate susceptibility, and yellow areas indicate low susceptibility.
Authors: Tharini Jeyaprakash, Marine Karepetyan, Michael Brown, Claire Shipman, Deepak Kumar
Science Advisors/Mentors: Dr. Bernard Eichold, Joe Spruce, Dr. Kenton Ross, Karen Jordan, Cheri Miller
Abstract: In April 2011, a string of tornadoes devastated much of the Southeast. According to the National Climatic Data Center, Alabama was the hardest hit state, with 53 confirmed tornadoes on April 27 alone. Hundreds lost their lives, homes were destroyed, and natural resources were greatly damaged. Damage was assessed by the Alabama Forestry Commission and according to their April tornadoes timber damage report 204,590 acres of forest land were affected with an assessed value of $266,088,751. The downed and damaged trees are expected to become breeding grounds for pine beetles. If this occurs, these pine beetles may then spread to stressed trees that border impact zones. To mitigate this problem, an analysis of pine beetle infestation risk in Tallapoosa County was completed for the Alabama Forestry Commission (AFC) by using NASA satellite images. Normalized Difference Moisture Index (NDMI) was computed on Aqua MODIS imagery to illustrate moisture levels in the entire state of Alabama after the tornado outbreak. Landsat 5 TM images were used to formulate an innovative Composite Risk Index (CRI) that determines a forest’s susceptibility to infestation. The CRI model employs three parameters: proximity to tornado paths, forest classification type, and NDMI. The project’s method will help to determine the most probable locations of future infestations through pine beetle damage risk maps for areas prone to imminent beetle infestation. These spectral indices, risk analysis, and a detailed methodology will be provide the AFC an efficient means of focusing their resources and restoration efforts, and improving future predictions.
Video transcript available here.