中文摘要：

以应用广泛的危险气体扩散模式SLAB为例，对此类模型在扩散过程中风向和风速保持不变的不合理假设进行了探讨，提出了改进的方法和思路．通过时间单元划分和坐标系旋转平移的方法使SLAB模式能在变化的风向风速条件下进行危险气体的扩散计算，该计算理念更真实地反映实际情况，从而更好地为应急管理部门提供及时、准确的决策支持，最大程度地降低危险事故造成的各项损失．

英文摘要：

This study developed an improved model for the dispersion of released toxic gases based on the widely used model SLAB. A major improvement enhanced the model＇ s ability to represent observations. SLAB was upgraded to account for temporal variation in wind vectors. In the method, the gas diffusion process was divided into several time intervals, and the algorithms of coordinate rotation and coordinate translation were used to make real-time changes in meteorological conditions which should be considered in dispersion forecasting. Theoretically, the results of improved SLAB better reflect the true conditions. Thus, the improved model can provide decision makers with timely and accurate guidance, so as to minimize hazards to people and the environment.