Department of Coastal & Urban Risk & Resilience, IHE Delft Institute for Water Education, P.O. Box 3015, 2601 DA, Delft, The Netherlands.
Department of Water Engineering & Management, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
Sci Rep. 2021 Nov 25;11(1):22921. doi: 10.1038/s41598-021-01945-5.
Climate change is widely expected to affect the thousands of small tidal inlets (STIs) dotting the global coastline. To properly inform effective adaptation strategies for the coastal areas in the vicinity of these inlets, it is necessary to know the temporal evolution of inlet stability over climate change time scales (50-100 years). As available numerical models are unable to perform continuous morphodynamic simulations at such time scales, here we develop and pilot a fast, probabilistic, reduced complexity model (RAPSTA - RAPid assessment tool of inlet STAbility) that can also quantify forcing uncertainties. RAPSTA accounts for the key physical processes governing STI stability and for climate change driven variations in system forcing. The model is very fast, providing a 100 year projection in less than 3 seconds. RAPSTA is demonstrated here at 3 STIs, representing the 3 main Types of STIs; Permanently open, locationally stable inlet (Type 1); Permanently open, alongshore migrating inlet (Type 2); Seasonally/Intermittently open, locationally stable inlet (Type 3). Model applications under a high greenhouse gas emissions scenario (RCP 8.5), accounting for forcing uncertainties, show that while the Type 1 STI will not change type over the twenty-first century, the Type 2 inlet may change into a more unstable Type 3 system around mid-century, and the Type 3 STI may change into a less unstable Type 2 system in about 20 years from now, further changing into a stable Type 1 STI around mid-century. These projections underscore the need for future adaptation strategies to remain flexible.
气候变化预计将广泛影响全球海岸线遍布的数千个小型潮汐入口 (STIs)。为了为这些入口附近的沿海地区提供有效的适应策略，需要了解气候变化时间尺度（50-100 年）下入口稳定性的时间演变。由于现有数值模型无法在如此长的时间尺度上进行连续的形态动力学模拟，因此我们在这里开发并试行一种快速、概率性、简化复杂性的模型 (RAPSTA - 入口 STI 稳定性的快速评估工具)，该模型还可以量化强迫不确定性。RAPSTA 考虑了控制 STI 稳定性的关键物理过程，以及系统强迫因气候变化而产生的变化。该模型非常快速，在不到 3 秒的时间内提供 100 年的预测。在此，RAPSTA 在 3 个 STIs 上进行了演示，代表了 STIs 的 3 种主要类型；永久开放、位置稳定的入口 (Type 1)；永久开放、沿程迁移的入口 (Type 2)；季节性/间歇性开放、位置稳定的入口 (Type 3)。在高温室气体排放情景 (RCP 8.5) 下应用模型，并考虑强迫不确定性，结果表明，虽然 Type 1 STI 在 21 世纪内不会改变类型，但 Type 2 入口可能会在本世纪中叶左右转变为更不稳定的 Type 3 系统，而 Type 3 STI 可能会在大约 20 年后转变为不太稳定的 Type 2 系统，并在本世纪中叶左右转变为稳定的 Type 1 STI。这些预测强调了未来适应策略需要保持灵活性。
