EBTAG Annual Workshop and Field Trip
May 16-17, 2012

¹New Mexico Highlands University, alavadie@live.nmhu.edu

²New Mexico Forest and Watershed Restoration Institute

Climate change that results in drier, warmer climates has the potential to increase fire occurrence and intensify fire behavior. The rate of erosion on landscapes exposed to wildfire disturbance will increase. Following large fires, surface water runoff contributes high concentrations of nutrients to water bodies and has the potential to impair surface water quality and terrestrial systems. Several studies outline the effects of fire on nutrient concentrations in streams following a fire. However, there is a need to directly investigate nutrient levels transported in surface runoff from specific burn severity classes.  In addition, burn severity assessment standards and terminology are limited to remote sensing technology. Burn Area Emergency Response (BAER) teams have often struggled with accurately mapping post-fire soil burn severity and have recognized the need for consistent methodologies, assessment tools, and terminology that quickly and accurately identify on the ground post-fire conditions. As a result they are led to use geospatial assessment tools that have little standardization in field verification.

The first purpose of this study is to compare Landsat thematic mapper and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) technology with ground measurements to further refine methodology to standardize burn severity class. To complete this task we will take on-site field measurements in High, Moderate and Low burn severity sites as categorized by the USGS and Monitoring Trends in Burn Severity program (MTBS) to accurately characterize each fire severity class. We will then compare these measurements to Landsat, ASTER-derived burn severity map data to determine if remote sensing fire severity classifications appropriately represent ground measurements. The second purpose of this study is to investigate the contributions of nitrate (NO₃), nitrite (NO₂), organic nitrogen (ON), total phosphate (TP), orthophosphate (OP) and total suspended solids (TSS) concentration levels from surface water runoff originating in various wildfire severity classes from the Las Conchas fire in the Jemez Mountains, New Mexico. To complete this task, the above mentioned nitrogen and phosphorus constituents will be measured and analyzed from surface water runoff flowing from an unburned Control site and predetermined High, Moderate, Low, and Mixed (inclusive of low, moderate and high severity sites) fire severity types.