Modelling tsunami induced coarse clast transport , combination of physical experiments, advanced numerical modelling and field observations

模拟海啸引起的粗碎屑迁移，结合物理实验、高级数值模拟和现场观测

基本信息

批准号：
298757467
负责人：
Dr. Max Engel
金额：
--
依托单位：
Lehrstuhl und Institut für Wasserbau und Wasserwirtschaft
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/298757467?language=en
关键词：
Modelling tsunami induced coarse clast

项目摘要

While coastal areas are highly attractive for population and industry, they are also highly exposed to extreme-wave events (tsunamis, storm surges). Considering the expected continuing population and industrial growth, there is an urgent need to assess frequency-magnitude relationships and damage potentials with high accuracy. Based on such assessments, it is possible to develop hazard management plans and hazard-mitigation strategies. Even though high-magnitude tsunamis may cause disastrous impacts, their recurrence intervals are in the range of hundreds to thousand years. Thus, at particular coasts with short historical records, no observations or even measurements of such worst-case scenarios might be available. In this case marine sediments deposited onshore provide, evidence for an extreme-flooding event. By associating specific sediment characteristics with the necessary wave-energy for particle movements, distinct characteristics of the hydrodynamic process inducing the sediment transport (tsunami or storm surge/wave setup-up) can be derived. Since subaerial blocks and boulders are more resistant towards erosion and human impact as fine sediments, they are more suitable for such investigations. However, distinguishing between storm and tsunamis is in most cases a tough task. Numerical models can support such interpretations, but still suffer from several simplifications as negligence of sedimentary load, interactions between multiple boulders or complex boulder shapes. Furthermore, these factors are also neglected in state-of-the-art physical laboratory experiments. Likewise, only experiments utilizing idealised shaped body-models on uniform shaped bathymetries and coastal topographies are known.The proposed project aims at bridging four substantial gaps in the state-of-the-art. Firstly, the behaviour of (i) complex and idealised model boulders and (ii) interactions between them during the tsunami runup will be analysed and compared by laboratory experiments. Investigations of the influences on boulder transport mode, path, and distance due to (iii) non-uniform bathymetric settings and (iv) sedimentary load follow afterwards. The next step comprises the development, calibration, and validation of a numerical two-phase model by using results of the physical experiments. Based on photo-technically recorded and numerically implemented data for topography and block deposits, the model shall be able to simulate tsunami-induced transport events with an unprecedented accuracy by project close-out. For the post-project future, the model application is intended for the island of Bonaire (Netherlands Antilles), where the coastal boulder sedimentology is already documented in high detail.

尽管沿海地区对人口和行业具有很高的吸引力，但它们也暴露于极端波动的事件（海啸，风暴潮）。考虑到预期的持续人口和工业增长，迫切需要以很高的精度评估频率降低的关系和损坏潜力。根据此类评估，可以制定危害管理计划和减轻危害的策略。即使高磁性海啸可能会造成灾难性影响，它们的复发间隔仍在数百到千年的范围内。因此，在特定的历史记录短的沿海地区，可能没有观察到这种最坏情况的观察甚至测量值。在这种情况下，陆上存放的海洋沉积物提供了极端洪水事件的证据。通过将特定的沉积物特性与颗粒运动的必要波能量相关联，可以得出流体动力学过程的不同特征，诱导沉积物传输（海啸或风暴潮/波浪设置）。由于地下块和巨石对侵蚀和人类影响更具侵蚀，因此它们更适合于此类研究。但是，在大多数情况下，区分风暴和海啸是一项艰巨的任务。数值模型可以支持这种解释，但仍然遭受了几种简化的沉积负载，多个巨石之间的相互作用或复杂的巨石形状的相互作用。此外，这些因素在最先进的物理实验室实验中也被忽略了。同样，只有在均匀形状的测深和沿海地形上利用理想化形状模型的实验。拟议的项目旨在弥合最先进的艺术品中的四个巨大差距。首先，将通过实验室实验分析（i）（i）复杂和理想化的模型巨石以及（ii）它们之间的相互作用。（iii）不均匀的测深环境和（iv）沉积负载对巨石传输模式，路径和距离的影响进行了研究。下一步包括使用物理实验的结果对数值两相模型的开发，校准和验证。基于图形和数值实现的地形和块沉积数据的数据，该模型应能够通过项目封闭式以前所未有的精度模拟海啸诱导的运输事件。对于项目后的未来，该模型申请旨在用于Bonaire岛（荷兰Antilles），那里的沿海巨石沉积物学已经进行了高度详细记录。