Department of Geography, Durham University, Durham DH1 3LE, United Kingdom;
Department of Geography, Durham University, Durham DH1 3LE, United Kingdom.
Proc Natl Acad Sci U S A. 2018 Oct 9;115(41):E9532-E9541. doi: 10.1073/pnas.1807433115. Epub 2018 Sep 24.
High death tolls from recent earthquakes show that seismic risk remains high globally. While there has been much focus on seismic hazard, large uncertainties associated with exposure and vulnerability have led to more limited analyses of the potential impacts of future earthquakes. We argue that as both exposure and vulnerability are reducible factors of risk, assessing their importance and variability allows for prioritization of the most effective disaster risk-reduction (DRR) actions. We address this through earthquake ensemble modeling, using the example of Nepal. We model fatalities from 90 different scenario earthquakes and establish whether impacts are specific to certain scenario earthquakes or occur irrespective of the scenario. Our results show that for most districts in Nepal impacts are not specific to the particular characteristics of a single earthquake, and that total modeled impacts are skewed toward the minimum estimate. These results suggest that planning for the worst-case scenario in Nepal may place an unnecessarily large burden on the limited resources available for DRR. We also show that the most at-risk districts are predominantly in rural western Nepal, with ∼9.5 million Nepalis inhabiting districts with higher seismic risk than Kathmandu. Our proposed approach provides a holistic consideration of seismic risk for informing contingency planning and allows the relative importance of the reducible components of risk (exposure and vulnerability) to be estimated, highlighting factors that can be targeted most effectively. We propose this approach for informing contingency planning, especially in locations where information on the likelihood of future earthquakes is inadequate.
近期地震造成的高死亡率表明，全球地震风险仍然很高。虽然人们已经非常关注地震灾害，但由于暴露和脆弱性方面存在很大的不确定性，因此对未来地震可能造成的影响进行的分析有限。我们认为，由于暴露和脆弱性都是风险的可减少因素，因此评估它们的重要性和可变性可以优先考虑最有效的灾害风险减少（DRR）措施。我们通过地震集合模型来解决这个问题，以尼泊尔为例。我们对 90 次不同情景地震造成的死亡人数进行建模，并确定这些影响是特定于某些情景地震，还是无论情景如何都会发生。我们的结果表明，对于尼泊尔的大多数地区，影响并非特定于单次地震的特定特征，而且总模型影响偏向于最小估计值。这些结果表明，在尼泊尔为最坏情况做规划可能会给本就有限的 DRR 资源带来不必要的负担。我们还表明，风险最高的地区主要集中在尼泊尔西部农村地区，约有 950 万尼泊尔人居住在地震风险高于加德满都的地区。我们提出的方法全面考虑了地震风险，为应急规划提供了信息，并可以估计风险的可减少组成部分（暴露和脆弱性）的相对重要性，突出了可以最有效地针对的因素。我们建议在应急规划中采用这种方法，特别是在未来地震可能性的信息不足的地方。
