Treesearch

A field deployable system for quantifying energy and mass transport in wildland fires is described. The system consists of two enclosures: The first is a sensor/data logger combination package that allows characterization of convective/radiant energy transport in fires. This package contains batteries, a programmable data logger, sensors, and other electronics. The standard sensors consist of radiometers that measure total and radiant energy fluxes, a small-gauge thermocouple that senses flame and air temperature, and probes that sense the magnitude and direction of airflow before, during,...

Perhaps one of the most critical decisions made on wildland fires is the identification of suitable safety zones for firefighters during daily fire management operations. To be effective (timely, repeatable, and accurate), these decisions rely on good training and good judgement. The current safety zone guidelines used in the US (see fig. 1) and published in the Incident Response Pocket Guide (IRPG) and Fireline Handbook were developed based on the assumption that the fire and safety zone were located on flat terrain. The minimum safe distance for a firefighter to be from a flame was...

Data collected in the International Crown Fire modeling Experiment during 1999 are evaluated to characterize the magnitude and duration of convective energy heating in full scale crown fires. To accomplish this objective data on total and radiant incident heat flux, air temperature, and horizontal and vertical gas velocities were evaluated. Total and radiant energy fluxes were measured. Temperatures were measured using bare Type K 0.13 mm wire diameter thermocouples. Gas velocities were measured using pitot-static type sensors designed specifically for velocity measurements in fires. The...

In this presentation we review progress towards the implementation of a risk-based management framework for U.S. Federal wildland fire policy and operations. We first describe new developments in wildfire simulation technology that catalyzed the development of risk-based decision support systems for strategic wildfire management. These systems include new analytical methods to measure wildfire risk to human and ecological values and to inform fuel treatment investment strategies at national, regional, and local scales. Application of risk assessment to support wildfire incidents has been...

Recent high intensity wildfires and our demonstrated inability to control extreme fire behavior suggest a need for alternative approaches for preventing wildfire disasters. Current fire spread models are not sufficiently based on a basic understanding of fire spread processes to provide more effective management alternatives. An experimental and theoretical approach for improved understanding is necessary particularly for shrub and tree canopy fuels. Preliminary experiments of radiation heating resulted in coarse fuels (12-mm cross-section) heating to ignition while fine fuels (1-mm...

Components of a quantitative risk assessment were produced by simulation of burn probabilities and fire behavior variation for 134 fire planning units (FPUs) across the continental U.S. The system uses fire growth simulation of ignitions modeled from relationships between large fire occurrence and the fire danger index Energy Release Component (ERC). Simulations of 10,000-50,000 years were performed using artificial weather sequences generated by time-series analysis of recorded ERC values at local weather stations. Also needed were monthly distributions of wind speed and direction, as...

We couple laboratory work, airborne and ground-based field measurements, remote sensing of fires, and modeling to assess the impact of diverse types of biomass burning (BB) in Mexico as a model tropical country. About 70-80% of open BB occurs in the tropics along with large amounts of biofuel use and garbage burning (GB); both in rural and urban areas. During the Mexican dry season two instrumented aircraft measured emission factors (EF) from 57 fires including crop residue, tropical forest deforestation, pine forest, and savanna fires and GB. A mobile ground-based lab sampled 22 fires...

The Fire Lab at Missoula Experiments (FLAME) used a series of open biomass burns, conducted in 2006 and 2007 at the Forest Service Fire Science Laboratory in Missoula, MT, to characterize the physical, chemical and optical properties of biomass combustion emissions. Fuels were selected primarily based on their projected importance for emissions from prescribed and wild fires in the U.S. In a series of publications that will be overviewed here, we characterized the gas- and aerosol-phase emissions from the open combustion of 33 different plant materials in 255 laboratory burns. We reported...

Aerosols play important roles in adverse health effects, indirect and direct forcing of Earth’s climate, and visibility degradation. Biomass burning emissions from wild and prescribed fires can make a significant contribution to ambient aerosol mass in many locations and seasons. In order to better understand the chemical properties of particles produced by combustion of wild land fuels, an experiment was conducted in 2009 at the U.S. Forest Service/United States Department of Agriculture (USFS/USDA) Fire Science Laboratory (FSL) located in Missoula, Montana, to measure volatility of open...

Biomass burning is a major global emission source for trace gases and particulates. Various multi-platform measurements during the Mexico City Metropolitan Area (MCMA)-2003 and Megacity Initiative: Local and Global Research Observations (MILAGRO)-2006 campaigns suggest significant influences of biomass burning (BB) on air quality in Mexico City during the dry season, and the observations show emissions from BB impose viable yet highly variable impacts on organic aerosols (OA) in and around Mexico City. We have developed emission inventories for forest fires surrounding Mexico City based on...