USDA Forest Service

Fire and Environmental Research Applications Team


Fire and Environmental Research Applications Team
Pacific Wildland Fire Sciences Laboratory

400 N 34th Street, Suite 201
Seattle, WA 98103

(206) 732-7800

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United States Department of Agriculture Forest Service.

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Modeling Emissions for Prescribed Burning
A smoke emissions production model (EPM) was developed by the USDA Forest Service, Pacific Northwest (PNW) Research Station about 10 years ago. Since then, the model has been coded into a computer module and integrated into a variety of other computer programs. The module, EPM, currently is being used as the driving engine for a number of smoke dispersion models. Because of its increased use, PNW's Fire and Environmental Research Applications (FERA) team reanalyzed many of EPM's components to ensure proper support is provided to new applications of smoke dispersion modeling.

Data gathered from in-situ sampling of emissions from over 80 prescribed fires were used to analyze and calibrate EPM. The data were plotted as fuel consumption rate curves. The shapes of the rate curves were compared to duration of flaming, time-to-start flaming, time-to-finish smoldering, peak emissions, and total emissions. The qualitative comparisons showed that EPM adequately describes emissions for broadcast slash burns of relatively high intensity in northwest hardwoods and conifers. Data from 13 of the 80 field tests were available for a quantitative review of the model components. These were used to modify equations for predicting the emission decay rate during the initial smoldering phase of burns.

The Emissions Production Model was originally developed for broadcast prescribed burning of clearcut timber harvest residues in Pacific Northwest conifers. Many smoke dispersion modelers, however, are using EPM to estimate emissions from pile burns, understory burns of low intensity, prescribed natural fires, and in a variety of fuel types across the country. Therefore, suggestions on how to improve EPM for wider applications are given. In particular, improved data collection methods and analysis techniques are suggested for improving the long-term, residual smoldering component that is common in low-intensity burn applications.

S.A. Ferguson and C.C. Hardy. 1994. Modeling Emissions for Prescribed Burning. Presented at the 12th Conference on Fire and Forest Meteorology, Jekyll Island, Georgia, October 26-28, 1993.

U.S. Forest Service - PNW- FERA
Last Modified: Monday, 16 December 2013 at 14:18:40 CST

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