Effects of meteorological conditions on the concentration and dispersion of an accidental release of H2S in Canada

This study aims to determine the effects of the land's meteorological conditions on the dispersion of an accidental release of H2S using the CALPro software. The three Canadian cities or towns of Edmonton, Yarmouth and Whitehorse, which are all of different meteorological conditions, were chosen as the domains of study. Hourly geophysical, surface and upper air meteorological data were used with CALMET to model the wind field of the three domains for the modeling period of March 11, 2012 from 00h00 to 23h00 LST. Individual 5-h modeling periods where the wind field showed the most significant variations were chosen for each region of study. CALPUFF was used to model the dispersion effects of an accidental release of H2S from a single point source due to an accidental vessel puncture using time-varying emission data modified to suit each region's modeling period. Despite the wind reversal encountered in Edmonton, its relatively flat terrain allowed H2S to disperse outwards, causing concentrations to accumulate lower than the other two regions but still to sever levels and a much greater population. Differences between the effect of land and sea breeze on H2S dispersion in Yarmouth's coastal region caused concentrations to accumulate higher than the other two regions and to life threatening levels around the source. The mountainous terrain of Whitehorse shaped the plume trajectory, causing H2S concentrations to accumulate to levels that can cause irreversible health effects at various times and locations. Results show that each area's meteorological conditions will have different impacts on dispersion.