Explain air quality dispersion modeling and how it is used in EIA.

Dispersion models predict pollutant concentrations from emission sources using meteorological data and source characteristics. Gaussian plume models (AERMOD, ISCST3) assume steady-state conditions with normal distribution of concentrations. Inputs: emission rate, stack parameters (height, diameter, exit velocity, temperature), meteorological data (wind speed/direction, stability class), and terrain. Models calculate ground-level concentrations for comparison with standards. In EIA, modeling predicts impacts of proposed projects, determines stack height requirements, and designs control measures. Validation against monitored data essential.