State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China.
Risk Anal. 2013 Jan;33(1):134-45. doi: 10.1111/j.1539-6924.2012.01838.x. Epub 2012 May 22.
New features of natural disasters have been observed over the last several years. The factors that influence the disasters' formation mechanisms, regularity of occurrence and main characteristics have been revealed to be more complicated and diverse in nature than previously thought. As the uncertainty involved increases, the variables need to be examined further. This article discusses the importance and the shortage of multivariate analysis of natural disasters and presents a method to estimate the joint probability of the return periods and perform a risk analysis. Severe dust storms from 1990 to 2008 in Inner Mongolia were used as a case study to test this new methodology, as they are normal and recurring climatic phenomena on Earth. Based on the 79 investigated events and according to the dust storm definition with bivariate, the joint probability distribution of severe dust storms was established using the observed data of maximum wind speed and duration. The joint return periods of severe dust storms were calculated, and the relevant risk was analyzed according to the joint probability. The copula function is able to simulate severe dust storm disasters accurately. The joint return periods generated are closer to those observed in reality than the univariate return periods and thus have more value in severe dust storm disaster mitigation, strategy making, program design, and improvement of risk management. This research may prove useful in risk-based decision making. The exploration of multivariate analysis methods can also lay the foundation for further applications in natural disaster risk analysis.
近年来，人们观察到了自然灾害的新特征。与之前的认识相比，影响灾害形成机制、发生规律和主要特征的因素在本质上更加复杂和多样化。随着不确定性的增加，需要进一步检查变量。本文讨论了对自然灾害进行多元分析的重要性和不足，并提出了一种估计重现期联合概率并进行风险分析的方法。以内蒙古 1990 年至 2008 年的严重沙尘暴事件为例，对这种新方法进行了检验，因为沙尘暴是地球上常见的、周期性的气候现象。基于 79 次调查事件，并根据二元沙尘暴定义，利用最大风速和持续时间的观测数据，建立了严重沙尘暴的联合概率分布。根据联合概率计算了严重沙尘暴的联合重现期，并对相关风险进行了分析。该 Copula 函数能够准确地模拟严重沙尘暴灾害。生成的联合重现期比单变量重现期更接近实际观测到的重现期，因此在减轻严重沙尘暴灾害、制定策略、设计方案以及改进风险管理方面更具价值。该研究有助于基于风险的决策制定。探索多元分析方法还可以为进一步应用于自然灾害风险分析奠定基础。
