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

联合国呼吁将警报系统覆盖到地球上的每个人。与其他更频繁的灾害相比，海啸事件造成的损失最大。印度的海岸线是世界上人口最多的地区之一，容易受到由俯冲带（如马克兰、巽他海沟北部）和海底滑坡引发的海啸的影响。这些事件的到达时间从安达曼尼科巴群岛的15分钟到大陆的2-3小时不等。在这个时间尺度上，有效的预警和准备行动可以挽救许多生命。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者。在当地参与的基础上，通过提高ITEWC的实际和业务能力，PCTWIN采取了具体步骤，确保社区更具抗灾能力。PCTWIN的目标与以人为本的早期预警的支柱相一致：改善灾害风险知识；加强对海啸的探测、观测和预报；更有效和更具包容性的海啸预警通信；增加了防范。海啸成因的物理知识为未来大型逆冲地震的预期特征和频率提供了宝贵的见解。PCTWIN将使用苏门答腊-安达曼地区的GNSS站来解决2004年苏门答腊大地震后20年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源海啸，使受灾人口没有时间安全撤离。例如2018年的苏拉威西和巽他海峡海啸。PCTWIN通过对海啸型海底滑坡源的综合表征，突破了前沿研究的界限。这将为包括滑坡源的海啸预报铺平道路。海啸预报和预警方面存在若干业务和技术挑战，如早期震源特征的高度不确定性、数据及时同化和后处理方面的差距以及对不确定性的有效通报。PCTWIN促进了从确定性到概率海啸预报的范式转变，为下一代印度海啸预警系统提供灵活的情景构建。这需要共同设计预警不确定性的通信，并通过实时多通道数据同化来减少不确定性，特别是通过实现5分钟内快速源表征的大地测量数据。PCTWIN不仅努力在不同的尺度上预测危害，而且还预测影响，从低分辨率的国家尺度到高分辨率的地方尺度，在选定的热点地区作为未来的试点。对于到达时间较短的近源海啸，做好准备和准备采取行动可以挽救许多生命。情景意识和风险认知差距，特别是在融入弱势群体方面的差距，是社区抵御海啸能力的严重障碍。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。这得益于教科文组织在印度洋地区的倡议，如“海啸应对识别计划”的协同作用。PCTWIN通过引入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，补充了海啸防备指标。PCTWIN努力使所有处于危险中的社区都能做好海啸准备，它将共同设计和共同制定最佳实践指南，使社区做好海啸准备，抵御海啸。

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.