Three-dimensional visualization of harmful gas diffusion in an urban area

This paper simulated a harmful gas diffusion in an urban area. Based on the Gaussian Plume Model, the simulation was performed in the 3D virtual environment of the Digital Earth Scientific Platform, which was established by the Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS). This paper calculated the spread distance of harmful gas in every direction and the concentration of a certain point near to the accident point. The spread range of the gas with same concentration could be drawn in the scene and the 3D range affected by the gas diffusion accident also could be performed as well. The result showed that combining the Gaussian Plume Model with GIS technology we can show the affected range clearly in the scene by using curved surface with different color and transparency, which was much better than the common two-dimensional visualization. Besides, this paper also discussed the way to count the number of people who might be affected by the harmful gas, trying to make sense in emergency evacuation and city planning