用概率化物理代理模型,高效预测海啸波高与到达时间。
Reduced Order Modeling for Tsunami Forecasting with Bayesian Hierarchical Pooling
- 构建基于贝叶斯分层聚合的修正降维模型,突破传统固定系数限制。
- 在斐济和2011年东日本海啸案例中,仅需少量全量模拟即实现精准预测。
- 适合需要快速、可信海啸预警的应急响应与灾害规划场景。
降维模型(ROM)能以更少维度表征时空过程,求解速度比原始偏微分方程快数个数量级。本文提出一种修正的伽辽金投影降维模型,以初始值问题形式编码物理规律,并通过算子校正精确还原系数动态。结合贝叶斯分层聚合框架对初始降维系数进行建模,生成可解释且物理解释明确的系数轨迹,实现跨相似情景的泛化。将这些轨迹与空间模态重构后,得到完整的概率性物理代理模型(randPROM),可生成分布上与邻近初始条件一致的仿真结果。应用于海啸建模——这一涉及不可预测、灾难性且强非线性的场景,涵盖斐济区域合成案例及2011年东日本海啸真实事件。结果显示,randPROM显著减少全量模拟次数,同时提供统计校准、物理解释清晰的海啸波高与到达时间预测。
原文摘要 · Abstract (English)
Reduced-order models (ROMs) can represent spatiotemporal processes in significantly fewer dimensions and can often be solved many orders of magnitude faster than their governing partial differential equations (PDEs). For example, proper orthogonal decomposition yields a ROM in which the state is represented as a low-dimensional linear combination of fixed spatial modes and time-dependent coefficients, but this representation remains constrained by the process used to construct the basis. In this work, we explore a new type of ROM that is not restricted to a single fixed coefficient trajectory. Specifically, we consider a corrected Galerkin-projection ROM, formulated as an initial value problem that encodes the physics of the governing PDEs and is calibrated through operator corrections to more accurately reproduce the coefficient dynamics. By combining this corrected reduced model with a Bayesian hierarchical pooling framework over the initial reduced coefficients, we obtain new, statistically interpretable and physically grounded coefficient trajectories that generalize across related scenarios. When recombined with the spatial modes, these trajectories define a complete probabilistic physics surrogate, called a randPROM, for generating simulations that are distributionally consistent with a neighborhood of initial conditions near those used to construct the ROM. We apply the randPROM framework to tsunami modeling, a setting involving unpredictable, catastrophic, and strongly nonlinear dynamics, using both a synthetic case study near Fiji and the real-world 2011 Tohoku tsunami. We demonstrate that randPROMs can substantially reduce the number of full simulations required while providing statistically calibrated and physically defensible predictions of tsunami wave arrival times and heights.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。