Sevier County, TN Wildfire

 Tuck Mapping recently donated 3 inch orthophotography to Sevier County to aid in the relief efforts after the wildfires from November 2016 burned over 17,000 acres in less than five days.

On Wednesday, November 23, 2016, the acre-and-a-half blaze began near the top of a steep hill called Chimney Tops outside of Gatlinburg, TN. It was treated using forest-firefighting techniques that, partially because of safety concerned in the rugged terrain, involved organizing a break-line perimeter around 400 acres. The fire occurred after the deciduous trees had shed their leaves adding more fuel to the forest floor that was already abundant with desiccated leaves, twigs, dead branches, and logs that had been sucked dry of their moisture by the months of drought. The leafless trees allowed more sunlight to hit the fuel, drying it out even more.

Sunday, four days after the fire started, was the first time that any firefighting aircraft were used on the fire. However, the aircraft dropping water and fire retardant on a fire could not put it out. Under ideal conditions they can temporarily slow the spread, which may be effective if firefighters on the ground can move in quickly to take advantage of the short-term change in fire behavior by constructing fire breaks, stopping the spread at that location. In this case, there were no firefighters in a position to take direct action. The fire expanded only slightly to about 6 acres through November 27th.

On November 28th, humidity levels dropped to 10% with wind gusts up to 87 mph. Over the next three days, sustained winds of 40mph were recorded across the area. Wind gusts carried burning embers long distances causing new spot fires to ignite across the area. In addition, high winds caused numerous trees to fall throughout the evening on Monday bringing down power lines across the area that ignited additional new fires that spread rapidly due to sustained winds of over 40 mph.

Power went out for thousands of customers in Sevier County. Live wires are at least part of the reason the Chimney Top Fire spread so rapidly overnight. The Gatlinburg Fire Chief said “These are the worst possible conditions imaginable.” Of course, high winds and downed power lines don’t usually spark such devastating wildfires. The key ingredient in eastern Tennessee was the ongoing, severe drought. All of Sevier County is in an “exceptional drought,” which is the worst on the U.S. Drought Monitor Scale. It means there are widespread crop and pasture losses, shortages in water reservoirs, streams and wells. In short, eastern Tennessee has turned into a tinderbox. The fire spread from 80 acres to 17,000 acres before it showed any signs of slowing down.

Unfortunately, 14 people passed away as a result of the fire. 2,460 structures were damaged or destroyed and there was an estimated 842 million dollars’ worth of damage.

To assist in the relief efforts, Tuck Mapping donated 3 inch aerial orthophotography of the entire affected area to Sevier County. The County will use this data for: planimetric mapping of structures, identification of structure status, emergency response plans, emergency warning system plans, update of structure rebuilds for GIS, projection of revenues from property taxes, building permit updates, routing for building supplies, and future zoning of development areas.