USDA Forest Service Burned Area Emergency Response (BAER) is a multi-disciplinary team that assesses post-fire impacts on federal lands following significant wildfires. The role of the assessment team is to characterize fire effects within the burned area to identify imminent post-fire threats to human life, safety, property, infrastructure, and critical natural and cultural resources on National Forest System (NFS) lands and recommend emergency response actions designed to mitigate identified risks. After the assessment, Okanogan-Wenatchee National Forest land managers establish an organization to implement protective and stabilization treatments that will be approved by the Forest Service Regional and National offices.
The BAER team began their assessment immediately after the fire threat passed. Their focus was on direct effects to the burned landscape caused by the fire, rather than from fire activities which are the responsibility of the Incident Management Team (IMT) assigned to the fire. Post-fire effects such as loss of vegetation and change in soil stability commonly increase the likelihood of threats that include accelerated soil erosion, increased sediment delivery, flooding, and debris flows.
BAER specialists recently completed their field data evaluation to produce the Soil Burn Severity (SBS) map for the 113,689-acre Schneider Springs Fire. The map and the data delineated Unburned/Very Low, Low, Moderate and High SBS categories. Across the Schneider Springs burned area, approximately 21% of the fire is Unburned; 35% Low SBS; 19% Moderate SBS; and 17% High SBS. The remaining area was mapped as rock.
The acreage of landownership within the Schneider Springs Fire perimeter: 101,320 acres of Okanogan-Wenatchee National Forest (OWF) land 44,856 acres of the 101,320 OWF acres are wilderness; 11,872 acres of Washington State land; and 497 acres of private/other lands.
It is important to note the SBS map product is an estimate of fire effects on soils and not direct effects to vegetation. SBS characterizes the soil surface and below-ground impact, whereas effects on vegetation are estimates of mortality based primarily on changes in vegetation canopy. Changes in overhead and understory vegetation canopy are often used as initial indicators of overall burn severity, but do not necessarily coincide with SBS.
Changes in ground cover, water repellency, and soil physical/biological conditions guide the interpretations to determine a soil severity burn level. Water repellency can occur naturally in some soils and changes as a function of fire are frequently discussed as a post-fire effect. Fire can increase the strength and depth of water repellent layers in soil, considerably increasing post-fire rain runoff and may extend time for recovery for those soils.
A low category of soil burn severity indicates that there was a partial consumption of fine fuels and litter coverage remains, to some extent, on the soil surface. Residence time at the soil surface in low areas was short, leaving root systems and structure intact. Recovery time in the low category will vary based on ecological community but is expected to be relatively short.
A moderate category of soil burn severity indicates consumption of litter and fine fuels at the soil surface. In forested communities, the heat from moderate severity fire may result in water repellant conditions at the mineral soil surface. The canopy in the moderate forested system is browning and it is expected that trees in this area will drop needles and leaves that can provide some litter cover at the soil surface. In these systems, recovery can take longer for tree species to reestablish.
Moderate soil burn severity category in lower elevation communities indicates complete consumption of shrub cover that can but does not necessarily result in water repellant conditions at the soil surface. Several shrub species in the lower elevation communities do re-sprout from their burned root crowns after fire and recovery time will be variable. Moderate soil burn severity category in the lower elevation shrub communities that did not express water repellant behavior can still result in a rain runoff potential category of high as a result of the soils inherent qualities and the removal of effective ground cover.
A high soil burn severity category is the result of higher intensity fire behavior or longer residence time at the soil surface. This category is found in forested or dense Woodland communities and the litter and fuels, including an overstory canopy, that is consumed by the fire. The soil structure is weakened, roots are charred, and water repellant soil conditions can persist through the upper horizon of mineral soil. Recovery time in these conifer systems can be significantly longer
The Schneider Springs BAER assessment team used initial remote sensing imagery with field-validated soils data to produce the final SBS map. The BAER team and the US Geological Survey (USGS) both use the SBS map as an analysis tool to estimate post-fire erosion with subsequent sediment delivery, stream flows and debris flow probabilities.
Both the Schneider Springs Fire soil burn severity and runoff maps can be downloaded at the “Schneider Springs Post-Fire BAER” InciWeb site (https://inciweb.nwcg.gov/incident/7860/) as a JPEG or PDF version under the “Maps” tab.
SPECIAL BAER SAFETY MESSAGE: Everyone near and downstream from the burned areas should remain alert and stay updated on weather conditions that may result in heavy rains and increased water runoff. Flash flooding may occur quickly during heavy rain events and residents and forest visitors need to be prepared to take action. Current weather and emergency notifications can be found at the National Weather Service website: https://www.weather.gov/pdt/.