In this study, we use Pleiades satellite stereo imagery to map shallow-water bathymetry specifically for the purpose of assessing tsunami hazard in coastal regions. In order to calculate the refraction correction factor, we independently measure the refractive indices of seawater mixed with a variety of phytoplankton, which was previously unquantified. We find that the refractive index of seawater increases with cell density of phytoplankton, ranging from 1.3410 to 1.3425. Through rigorous error analysis, we demonstrate that the change in refraction due to heterogeneous distribution of phytoplankton is negligible, suggesting that the technique is applicable to the global ocean. Using the Penghu Islands as a case example, we show that photogrammetric bathymetry is able to reveal tsunami impacts more accurately and reasonably than the commonly used General Bathymetric Chart of the Oceans data, highlighting the importance of high-resolution and high-accuracy bathymetry for tsunami hazard assessment.

中文翻译：

---

从卫星摄影测量推导出海岸水深测量的通用方法用于海啸灾害评估

在这项研究中，我们使用 Pleiades 卫星立体图像来绘制浅水测深图，专门用于评估沿海地区的海啸灾害。为了计算折射校正因子，我们独立测量了与各种浮游植物混合的海水的折射率，这是以前未量化的。我们发现海水的折射率随着浮游植物细胞密度的增加而增加，范围从 1.3410 到 1.3425。通过严格的误差分析，我们证明浮游植物异质分布引起的折射变化可以忽略不计，表明该技术适用于全球海洋。以澎湖列岛为例，