Combined Modeling of US Fluvial, Pluvial, and Coastal Flood Hazard Under Current and Future Climates
Combined Modeling of US Fluvial, Pluvial, and Coastal Flood Hazard Under Current and Future Climates
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DOI：
10.1029/2020wr028673
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发表时间：
2021-02-01
影响因子：
5.4
通讯作者：
Krajewski, Witold F.
中科院分区：
文献类型：
--
作者：
Bates, Paul D.;Quinn, Niall;Krajewski, Witold F.
这项研究报告了一项新的、显著增强的美国洪水风险分析，其空间分辨率为30米。具体改进包括更新水文数据、确定河道深度的新方法、更严格的洪水频率分析、将输出缩减到属性区级，以及将当地干预措施的影响纳入洪水系统。我们首次在同一框架内考虑了洪涝、河流和沿海洪水灾害，并在RCP4.5排放路径下提供了对当前(而不是历史平均)条件和以2035年和2050年为中心的未来时间段的预测。根据高质量的当地模型和FEMA 1%年度概率洪水图的整个目录进行验证，得出的关键成功指数值在0.69-0.82之间。与以前的暴雨/河流模型版本相比，高频事件和沿海地区的情况有了显著的改进，在模型性能已经很好的地区也有了微小的改进。其结果是第一次全面和一致的全国范围内对当前和未来条件下的美国的洪水风险进行分析。尽管我们考虑了稳定排放的情景和近期的时间范围，但我们预测了洪水风险变化的明确模式(100年3西格玛变化淹没面积从-3.8%到+16%，在1度尺度上)，当考虑到人类可能使用的土地面积的比例时，或者就目前受保护的土地面积而言，这些变化是重要的，因为此时防洪保护标准可能会受到影响。
This study reports a new and significantly enhanced analysis of US flood hazard at 30 m spatial resolution. Specific improvements include updated hydrography data, new methods to determine channel depth, more rigorous flood frequency analysis, output downscaling to property tract level, and inclusion of the impact of local interventions in the flooding system. For the first time, we consider pluvial, fluvial, and coastal flood hazards within the same framework and provide projections for both current (rather than historic average) conditions and for future time periods centered on 2035 and 2050 under the RCP4.5 emissions pathway. Validation against high-quality local models and the entire catalog of FEMA 1% annual probability flood maps yielded Critical Success Index values in the range 0.69-0.82. Significant improvements over a previous pluvial/fluvial model version are shown for high-frequency events and coastal zones, along with minor improvements in areas where model performance was already good. The result is the first comprehensive and consistent national-scale analysis of flood hazard for the conterminous US for both current and future conditions. Even though we consider a stabilization emissions scenario and a near-future time horizon, we project clear patterns of changing flood hazard (3 sigma changes in 100 years inundated area of -3.8 to +16% at 1 degrees scale), that are significant when considered as a proportion of the land area where human use is possible or in terms of the currently protected land area where the standard of flood defense protection may become compromised by this time.