Efficient computational models for the optimal representation of correlated regional hazard Christou, Vasileios; Bocchini, Paolo
In this paper, a methodology is presented for the generation of an optimal set of maps representing the intensity of a natural disaster over a region. In regional hazard and loss analysis, maps like these are commonly used to compute the probability of exceeding certain levels of intensity at all sites, while also providing information on the correlation among the intensity at any pair of sites. The information on the spatial correlation between two locations is of utmost importance for the accurate disaster performance assessment of lifeline components and of distributed systems. However, traditional hazard maps (such as those provided by USGS) do not provide this essential information, but only the probability of exceedance of a specific intensity at the various sites, considered individually. Therefore, many researches have attempted to address this problem and incorporate correlation in their models, mainly with two basic approaches. The first approach includes analytic or computational methodologies to assess directly the correlation; the second approach is adopted by techniques for the selection of a representative set of intensity maps, ofter referred to as “regional hazard-consistent maps”. The methodology presented herein, which branches out from the previous two approaches, considers the intensity maps as random fields. By adopting this abstract perspective, the new methodology is particularly appropriate for a multi-hazard approach, and it can take advantage of tools for the optimal sampling of multi-dimensional stochastic functions. These tools ensure that the weighted ensemble of generated samples (i.e., intensity maps) tends to match all the probabilistic properties of the field, including the correlation. In fact, the samples generated by the proposed methodology fully capture the marginal hazard at each location and the correlated regional hazard. After the technique is presented, an application is provided, for the case of seismic ground motion intensity maps.
Item Citations and Data
Attribution-NonCommercial-NoDerivs 2.5 Canada