Tsunami risk for the Western Indian Ocean: steps toward the integration of science into policy and practice

2004年苏门答腊-安达曼海啸在印度东海岸造成约15 000人死亡，特别是在经济上也受到严重影响的脆弱社区。1945年，包括印度在内的300至4，000人死于印度西海岸的海啸，该海岸可能很快就会遭受另一场可能更大的事件。问题是：我们如何保护印度西海岸的社区免受未来海啸的影响？从长远来看，只有明智的规划才能减少风险，因为预警系统只能减轻海啸的后果。这个问题的答案将通过使用地质学，数值模拟和统计学更好地科学理解海啸危害来研究。土地使用和规划决定最好能防止人们在未来可能发生的海啸的剧烈影响的易受影响地区定居，需要根据现有的科学知识有效地执行、加强和宣传这些决定。这些地区目前没有或很少有海啸风险规划。这些决定必须在极不确定的情况下作出，必须反映当地对风险的态度，考虑到决定的经济价值，并尊重当局和社区的道德观点。三个主要目标是：1.分析地震引起的海啸风险，并量化其导致的最终沿海洪水的不确定性。了解城市化进程，特别是土地使用和规划决策，如何影响沿海淹没对社区的影响3。评估这些影响的不确定性、风险价值以及利益攸关方制定反映这些考虑因素的缓解和应对战略所需的信息。该项目将采取跨学科的方法，将灾害的自然科学建模、城市发展动态的社会分析以及对缓解政策目标的决策理论（包括道德）评估结合在一起。在第一次短期研究中，我们将重点关注印度的两个沿海城镇，旨在为未来更雄心勃勃的研究奠定基础。通过进行此类初步研究，我们可以评估对科学不确定性和社区价值观敏感的深入减灾规划的可行性，并尝试管理自然灾害的多学科方法。

The 2004 Sumatra-Andaman tsunami killed around 15,000 people on the Eastern coast of India, especially from vulnerable communities who were also deeply affected economically as a result. In 1945, between 300 and 4,000 people, including in India, were killed by a tsunami on the Western coast of India, and this coast is possibly exposed to another event soon, potentially larger. The question is then: how do we protect the communities settled on the Western coast of India from a future tsunami? In the long term, only wise planning can reduce exposure, as early warning systems only mitigate the tsunami consequences. The answer to this question will be examined through a better scientific understanding of the tsunami hazard using Geology, numerical simulations, and Statistics. The land use and planning decisions, that should ideally prevent people from settling in zones prone to the dramatic impacts of possible future tsunamis, need to be implemented, strengthened and communicated efficiently based on the science at hand. There is currently no or very little planning for tsunami risk in these regions. These decisions will have to be made under great uncertainties and must reflect local attitudes towards risk, account for the economic value of decisions, and respect the ethical views of the authorities and the communities. The three central aims will be to:1. Analyse the tsunami risk arising from earthquakes and quantify the uncertainties regarding eventual coastal inundations that it causes.2. Understand how urbanisation processes, and in particular land use and planning decisions, contribute to the impact of coastal inundation on communities3. Assess the uncertainties regarding these impacts, the value put at risk by them and the information required by stakeholders to develop mitigation and response strategies that reflect these considerations.This project will take an interdisciplinary approach that brings together natural scientific modelling of hazards, social analysis of urban development dynamic, and decision-theoretic (including ethical) evaluation of the aims of mitigation policies. In this first short-term study, we will focus on two coastal towns in India, with the intent of laying down the foundations for a more ambitious future study. By doing an initial study of this kind we can assess the feasibility of in depth mitigation planning that is sensitive to scientific uncertainty and to community values, and trial a multidisciplinary approach to managing natural hazards.