A numerical study of harmful gas dispersion based on CALPUFF model

Severe gas leakage accidents occasionally happened during the exploitation of high-sulfur gas, the consequent harmful gas dispersion could seriously impact the air quality, cause large-scale casualties and economic losses. Therefore, people’s comprehensive understanding of harmful gas dispersion in both spatial and temporal dimensions should be improved. This paper takes gas well blowout accident in Kai County, China, as the case study, simulates and analyzes the dispersion characteristics of the leaked gas, mainly focuses on H2S. The CALPUFF model is applied to execute the experiment, the detailed meteorological data, complex terrain data, wet deposition and chemical transformations are all under consideration. The result shows that due to different impact factors, such as complex terrain and gas density variations, H2S exposure risk was higher in the valley area than that on the mountain, which also explains why Xiaoyang and Gaowang villages have a great number of casualties. Besides, the analysis result is basically consistent with the historical local news and reported data, which demonstrated that our case study of H2S gas dispersion simulation is reasonable and reliable.