Columbia River Gorge National Scenic Area
U.S. Forest Service
Hood River, OR 97031
Soil Burn Severity Map is Finalized
October 1, 2017
Hood River, Oregon - The Burned Area Emergency Response (BAER) Team assigned to the Eagle Creek Fire has finalized the Soil Burn Severity (SBS) map. They have identified 15% of the fire area as having high burn severity and 30% with moderate burn severity. The remaining 55% has low or very low burn severity.
High burn severity is indicated by the burning of all or nearly all of the ground cover and surface organic matter (leaves, needles, and decaying plant matter), including fine roots. Moderate burn severity has consumption of up to 80% of the ground cover. In areas with low burn severity, much of the organic matter on the surface is not fully burned and roots are generally intact.
The higher the burn severity is, the less likely the soil is able to absorb water from rainfall and snow melt. Severely damaged soils will produce more and faster water runoff. They are also more prone to erosion and landslides.
Hydrologists will calculate expected increases in stream flows and erosion based on the mapped damage to the soils. Their calculations will help determine which bridges and culverts are unlikely to handle the higher water levels, and where flood damage is more probable.
Some areas within the burn area are naturally prone to earth movement. Using the SBS map, BAER Team geologists and soil scientists will run models that will identify areas that will have increased tendencies to slide. They will also identify “Values at Risk” likely to be damaged by any earth movement.
“Values at Risk” (VARs) include roads, buildings, recreation sites, trails, fish hatcheries, powerlines, streams, historic and cultural sites, and more. Some are on Forest Service lands, others are on state, private, or other lands.
BAER Team members will be looking at the potential hazards to VARs in the aftermath of the fire, prioritizing them based on what the models show. Proposals will be developed for emergency actions that can mitigate these hazards, and emergency funding will be requested. BAER proposals focus on federal lands, but the BAER Team is sharing the SBS and information about the identified hazards with other agencies to help them plan for potential problems.