HGSYSTEM: a review, critique, and comparison with other models

HGSYSTEM is a package of computer models for modeling release and atmospheric dispersion of hazardous substances, which has capabilities that may not be found together elsewhere (e.g., hydrogen fluoride/air/water thermodynamics, aerosol release, release and dispersion of mixtures, multi-component evaporation, downward vertical jets, plume lift-off, deposition, and street-canyon). There are, however, some shortcomings in its spill models and in the transition from a spill to a dispersion model. The model's strong and weak points and limited comparisons with ALOHA and DEGADIS are discussed herein.