Sensitivity Analysis Study Considering the Selection of Appropriate Land-Use Parameters in AERMOD Modeling Analyses
In the near future AERMOD PRIME will officially replace the Industrial Source Complex Short-Term model, Version 3 (ISCST3) as the preferred Environmental Protection Agency (EPA) air dispersion model. Unlike the ISCST3 model that requires the simple selection of urban or rural default settings, the AERMOD dispersion model has a meteorological pre-processor (AERMET) that requires the input of site-specific land use parameters corresponding to land-use categories, including albedo, Bowen ratio, and surface roughness. AERMET then “adjusts” the meteorological data based on these site-specific micrometeorological parameters for use in AERMOD. AERMOD’s sensitivity to these land-use parameters has become a hot topic in the air dispersion community because of the significant impact on ambient concentrations that may result due to sensitivity to input parameters. This paper investigates the relationship between surface characteristics and air dispersion impacts as well how these relationships are addressed by regulatory agencies. Furthermore, this paper presents case studies of how the evaluation of surface characteristics can play a significant role in regulatory review of air dispersion modeling.