SASEM (Simple Approach Smoke Estimation Model)

DESCRIPTION

According to the Huntana Web site, SASEM is a screening 1 planning level, Gaussian dispersion model designed to predict ground level particulate matter and visibility impacts from single sources in relative flat terrain in the western United States.  SASEM utilizes internally calculated plume rise and emission rates based on specified fuel types and configurations.  The model is limited to particulate matter and visibility impact assessments; simplicity requires several physical assumptions.

According to Miller, the Simple Approach Smoke Estimation Model (SASEM) is a tool for the analysis of smoke dispersion from prescribed fires (Sestak and Riebau 1988). It is a screening model, in that it uses simplified assumptions and tends to over predict impacts, yielding conservative results. If violations of air quality standards are not predicted by SASEM, it is unlikely that they will occur.

Inputs to the model include basic descriptions of the fuels, such as type and loading, expected fireline intensity, and expected burn duration. Windspeed and direction, dispersion conditions, and average mixing height are considered, as well as distance and direction of the fire from sensitive receptors. The model calculates fuel consumption and particulate emission factors from fuel loading and expected fireline intensity.

Model outputs include maximum particulate concentration and the distance from the fire at which it will occur, ranges of distances from the fire at which any primary or secondary particulate standards would be violated, and the reduction in visual range at selected receptors. Outputs are given in tabular fashion for a range of dispersion and windspeed conditions.

SCALE AND AREAS OF APPLICATION

SURVEY COMMENTS

Seventeen survey respondents reported using SASEM.  Most respondents scored SASEM as a very important tool to perform their jobs. Again, most SASEM users also scored the tool as being either "somewhat" or "very" good at doing what they wanted it to do. Interestingly, while 30% said there was no need to change, 70% said there was a "high" need to change to or develop a different tool.

BENEFITS (PROS)

COSTS (CONS)

RECOMMENDATIONS