基于影响图的溃坝临灾决策模型

A New Decision Model for Dam-Break Risk Management Using Influence Diagrams

溃坝灾害给生命财产带来严重威胁。溃坝临灾疏散是一种有效的降低溃坝风险的措施。疏散决策必须经过科学分析,因为过晚的疏散可能造成巨大的生命财产损失,而过早的疏散往往会带来不必要的疏散成本。本研究采用影响图(Influence Diagrams)建立了一个溃坝临灾决策模型。该模型通过获得最小的期望损失来选择最佳疏散时机。本文首先介绍影响图方法的基本概念;然后建立一个分析溃坝应急决策的影响图模型并确定该模型的先验概率值;最后通过贝叶斯更新的方法讨论本决策模型的参数敏感性和溃坝决策的规律性。该模型避免了常规决策树方法中各个事件互相独立的假设,考虑了各个影响因素以及决策方案之间的相互关系和不确定性。该模型集成了风险定性分析、风险定量评估和基于风险的决策三个模块,以实现合理和高效的决策分析。

Dam failures caused catastrophic disasters to human beings. Emergent evacuation of the population at risk （ PAR } before a dam-break is an efficient way to save human life and properties. A late decision may lead to loss of lives and properties, but a very early evacuation will incur unnecessary expenses. A new decision model for damfailure emergency management is developed using Influence Diagrams. The optimal time to evacuate the PAR is obtained with minimum expected total losses. The concepts of Influence Diagrams are first introduced. The structure of the decision model is then built and quantified with prior probabilities. Finally, the sensitivities of the parameters influencing the dam-break flood consequences and decision making are discussed. The model does not require the assumption of independence of parameters , hut considers the inter-relationships among these parameters as well as the corresponding uncertainties. The model provides a tool for efficient decision making for dam failure emergency management by a combination of three components ： qualitative risk analysis, quantitative risk analysis and decision making.