Numerical Study on the Chemical Hazard Aiming at the Security during 2008 Beijing Olympic Games

In this study, a comprehensive system was developed to meet the demand of the Security Guarding during 2008 Beijing Olympic Games. In the system, meteorological models, namely, MM5 and RAMS6.0, and a poisonous clouds diffusion model over complex terrain (CDM) were configured in a one-way off-line nested way. In the system, MM5 runs were performed in an real-time operational way with a horizontal resolution of 3000m, which took the output from a Global scale model (T213 from the Chinese Meteorological Administration, CMA) as the initial and boundary conditions, and the output from MM5 was used to drive the RAMS6.0 runs to provide a 36-hour prediction with a horizontal resolution of 1000m. The wind and turbulent field output from RAMS6.0 was sequentially used to drive CDM runs, which can provide the prediction of the concentration field and the dose field of the chemical clouds. During 2008 Beijing Olympic Games, the system was used to provide the scenario prediction results and the security target was set as National Stadium (known as bird´s nest), and the quantitative analysis of the hazard risk was performed based on the scenario prediction results.