People-Centered Tsunami early Warning for the INdian coastlines (PCTWIN)

联合国呼吁地球上的每一个人都被预警系统覆盖。与其他更频繁的灾害相比，海啸事件造成的损失最大。印度海岸线是世界上人口最多的地区之一，容易发生由Makran、Sunda海沟北部和海底山体滑坡等俯冲带产生的海啸。这些活动的到达时间从安达曼尼科巴群岛的15分钟到大陆的2-3个小时不等。在这个时间尺度上，有效的警告和准备行动可以拯救许多人的生命。印度海啸预警中心(ITEWC)是印度洋沿岸25个国家的官方海啸服务提供商。通过改善ITEWC的实际和业务能力，以当地参与为基础，PCTWIN采取具体步骤，确保社区具有更强的抗灾能力。PCTWIN的目标与以人为中心的早期预警支柱保持一致：改善灾害风险知识；改进海啸的探测、观测和预报；更有效和更具包容性的海啸预警通信；增加准备。海啸生源物理知识为未来大地震的预期特征和频率提供了宝贵的见解。PCTWIN将利用苏门答腊岛-安达曼地区的GNSS观测站，解决2004年苏门答腊岛大地震20年后的震后变形和应变积累的基本问题。非地震和非典型海啸源造成了致命的、近震源的海啸，使受灾人口没有时间安全疏散。2018年的苏拉威西和舜达海峡海啸就是一个例子。PCTWIN通过对海啸成因的海底滑坡来源的全面表征，推动了前沿研究的边界。这将为海啸预报包括滑坡震源铺平道路。与海啸预报和预警有关的若干业务和技术挑战，例如早期震源特征的高度不确定性、与数据及时同化和后处理有关的差距以及不确定因素的有效沟通。PCTWIN促进了从确定性海啸预测到概率海啸预测的范式转变，为下一代印度海啸预警系统提供了灵活的情景构建。这需要共同设计警报中不确定性的通信，并通过实时多通道数据同化减少不确定性，特别是通过实施大地测量数据，在5分钟内快速确定源特征。PCTWIN努力不仅预测灾害，而且在不同的尺度上预测从较低分辨率的国家尺度到较高分辨率的地方尺度的影响，作为未来的试点地点。对于到达时间较短的近源海啸，做好准备和准备行动可以拯救许多人的生命。情况认识和风险认知差距，特别是与接纳弱势群体有关的差距，是社区抵御海啸的严重障碍。PCTWIN采用包容性、地方性和参与性的方法，加强海啸风险社区的准备工作。这得益于与教科文组织在印度洋地区的倡议的协同增效作用，例如“海啸防备方案”。PCTWIN是对海啸准备指标的补充，引入了衡量当地社区制定的海啸应对计划的包容性和私营部门参与程度的标志。为了让所有处于危险中的社区都能获得海啸准备，PCTWIN将共同设计和共同制定最佳实践指南，使社区为海啸做好准备，并使其具有抗海啸能力。

The United Nations has called for every person on earth to be covered by warning systems. Tsunami events are responsible for greatest of losses compared to other more frequent hazards. The Indian coastlines, which are some of the most populated areas in the world, are prone to tsunamis generated from subduction zones such as Makran, the northern part of the Sunda trench and submarine landslides. The arrival time for these events could range between 15 minutes for the Andaman Nicobar Islands to 2-3 hours for the mainland. This is a time scale where effective warning and being prepared to act can save many lives. The Indian Tsunami Early Warning Centre (ITEWC) is an official tsunami service provider for 25 countries along the Indian Ocean Coasts. Through achieving improvements to the practical and operational capacities of ITEWC, grounded in local participation, PCTWIN takes concrete steps towards ensuring communities are more disaster resilient.The objectives of PCTWIN are aligned with the pillars of people-centred early warning: improving disaster risk knowledge; improved detection, observation, and forecasting of tsunamis; more effective and more inclusive tsunami warning communication; increased preparedness.Knowledge of the physics of tsunamigenic sources provides invaluable insights into the expected features and frequency of future large megathrust earthquakes. PCTWIN will use the GNSS stations in the Sumatra-Andaman region to tackle fundamental questions regarding post seismic deformation and strain accumulation 20 years after the great 2004 Sumatra Earthquake.Non-seismic and atypical tsunami sources have been responsible for deadly, near-source, tsunamis that have left no time for the affected populations to safely evacuate. Examples are the 2018 Sulawesi and Sunda Strait Tsunamis. PCTWIN pushes boundaries of frontier research by comprehensive characterization of tsunamigenic submarine landslide sources. This will pave the way for tsunami forecasting to include the landslide sources.There are several operational and technical challenges related to tsunami forecasting and early warning, such as high uncertainties in early source characterizations, gaps related to timely assimilation and post-processing of data, and effective communication of uncertainties. PCTWIN promotes a paradigm shift, from deterministic to probabilistic tsunami forecasting with flexible scenario building for the next generation of Indian tsunami early warning system. This entails co-design of communication of uncertainties in warnings and uncertainty reduction through real-time multi-channel data assimilation, especially through implementation of geodetic data for fast source characterization within 5 minutes. PCTWIN strives to forecast not only the hazard but also the impact, at different scales, from lower resolution national scale to higher resolution local scale at selected hotspots as pilot sites for the future.For near-source tsunamis with short arrival times, preparedness and readiness to act can save many lives. Situational awareness and risk perception gaps, especially related to inclusion of vulnerable groups, are serious barriers towards community resilience to tsunamis. PCTWIN embraces inclusive, local, and participatory methods for increasing the preparedness of the communities at tsunami risk. This is facilitated by synergies with UNESCO initiatives in the Indian Ocean region such as the Tsunami Ready Recognition Program. PCTWIN complements the Tsunami ready preparedness indicators by introducing markers measuring the inclusivity of the tsunami response plans devised by the local communities and engagement of the private sector.Striving to render tsunami readiness accessible to all communities at risk, PCTWIN will co-design and co-develop best practice guidelines for making communities tsunami ready and tsunami resilient.