Normand Jonathan C L, Heggy Essam
University of Southern California, Viterbi School of Engineering, Los Angeles, CA, 90089, USA.
University Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, 75005, France.
Nat Commun. 2024 Aug 20;15(1):6493. doi: 10.1038/s41467-024-49699-8.
The eastern Mediterranean basin is witnessing increased storm activity impacting populous urban coastal areas that historically were not prone to catastrophic flooding. In the fall of 2023, Storm Daniel struck the eastern coast of Libya, causing unprecedented flash floods with a tragic death toll and large-scale infrastructure damages. We use Sentinel-1A C-band SAR images to characterize the resulting flash flood erosion and sediment load dynamics across the watersheds and to map damages within coastal cities at their outlets. Our results suggest that sediment loading, resulting from surface erosion, increased the density of turbid streams. The above exacerbated the catastrophic impact of the flash floods in the coastal cities of Derna and Susah, where 66% and 48% of their respective urban surface have experienced moderate-to-high damages. Our findings highlight the increased vulnerability of coastal watersheds in arid areas within the eastern Mediterranean basin due to the forecasted increase in hydroclimatic extremes and call for a transformative coastal management approach to urgently implement nature-based solutions and land-use changes to mitigate these rising risks.
地中海东部盆地正经历着风暴活动的增加，这对人口密集的城市沿海地区造成了影响，而这些地区在历史上并不容易发生灾难性洪水。2023年秋季，丹尼尔风暴袭击了利比亚东海岸，引发了前所未有的山洪暴发，造成了惨重的人员伤亡和大规模的基础设施破坏。我们使用哨兵-1A C波段合成孔径雷达图像来描述由此产生的山洪侵蚀和流域内泥沙负荷动态，并绘制沿海城市河口处的受损情况。我们的结果表明，地表侵蚀导致的泥沙淤积增加了浑浊溪流的密度。上述情况加剧了德尔纳和苏萨沿海城市山洪暴发的灾难性影响，在这两个城市，分别有66%和48%的城市地表遭受了中度至高度破坏。我们的研究结果凸显了地中海东部盆地干旱地区沿海流域由于水文气候极端事件预计增加而变得更加脆弱，并呼吁采取变革性的沿海管理方法，紧急实施基于自然的解决方案和土地利用变化，以减轻这些不断上升的风险。
