Zhu Qingguang, Xing Fei, Wang Ya Ping, Syvitski Jaia, Overeem Irina, Guo Jin, Li Yuan, Tang Jieping, Yu Qian, Gao Jianhua, Gao Shu
Ministry of Education Key Laboratory for Coast and Island Development, Nanjing University, Nanjing 210093, China.
Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA.
Sci Adv. 2024 May 3;10(18):eadk1698. doi: 10.1126/sciadv.adk1698.
Deltas are threatened by erosion due to climate change and reduced sediment supply, but their response to these changes remains poorly quantified. We investigate the abandoned Yellow River delta that has transitioned from rapid growth to ongoing deterioration due to a river avulsion removing the sediment supply. Integrating bathymetric data, process observations, and sediment transport modeling, we find that while the subaerial delta was stabilized by engineering measures, the subaqueous delta continued to erode due to intensified storms, losing 39% of its mass deposited before the avulsion. Long-term observations show that winter storms initiate scouring of the subaqueous delta, contributing up to 70% of seabed erosion. We then analyze 108 global deltas to assess subaqueous delta erosion risks and identify 17 deltas facing similar situations of sediment decline and storm intensification during the past 40 years. Our findings suggest that subaqueous delta erosion must be integrated into delta sustainability evaluations.
三角洲正受到气候变化导致的侵蚀以及沉积物供应减少的威胁，但其对这些变化的响应仍缺乏充分量化。我们研究了废弃的黄河三角洲，由于河流改道切断了沉积物供应，该三角洲已从快速增长转变为持续恶化。通过整合水深数据、过程观测和沉积物输运模型，我们发现，虽然陆上三角洲通过工程措施得以稳定，但水下三角洲由于风暴加剧而继续侵蚀，损失了改道前沉积质量的39%。长期观测表明，冬季风暴引发了水下三角洲的冲刷，造成了高达70%的海床侵蚀。然后，我们分析了108个全球三角洲，以评估水下三角洲的侵蚀风险，并确定了在过去40年里面临沉积物减少和风暴加剧类似情况的17个三角洲。我们的研究结果表明，水下三角洲侵蚀必须纳入三角洲可持续性评估。
