This article discussed the extension of Copula joint distribution model in 3D multiple hazards for disaster comprehensive analysis. Based on three basic conditions of formation of severe dust storms: wind speed, abundant sand source and unstable atmospheric stratification, it established Copula joint distribution by the three basic characteristics of meridional index, the daily average maximum wind speed and soil moisture is established by taking dust storm events occurred in Xianghuanqi station in Inner Mongolia from 1990-2008 as a case. The return period under different encounter is calculated by the distribution.
The cases study indicates that the three-dimensional hazards of severe dust storm of Xianghuanqi well scalable ability to the construction conditions of the Frank Copula function. This function well described the joint distribution of the three variables of severe dust storms.By comparison with the return period bases on single variable and bivariable, the joint return periods with 3D variable are obtained with more realistic, and the 3D Frank Copula fits better occurrence probability on middle and high parts.