Hidden delta degradation due to fluvial sediment decline and intensified marine storms

• DOI: 10.1126/sciadv.adk1698
• Publication Date: 2024-05-03T17:58:53Z
• Authors: Qingguang Zhu; Fei Xing; Ya Ping Wang; Jaia Syvitski; Irina Overeem; Jin Guo; Yuan Li; Jieping Tang; Qian Yu; Jianhua Gao; Shu Gao
• Keywords: Subaerial; River delta; Coastal erosion; Overwash; Deposition

Deltas are threatened by erosion due to climate change and reduced sediment supply, but their response these changes remains poorly quantified. We investigate the abandoned Yellow River delta that has transitioned from rapid growth ongoing deterioration a river avulsion removing supply. Integrating bathymetric data, process observations, transport modeling, we find while subaerial was stabilized engineering measures, subaqueous continued erode intensified storms, losing 39% of its mass deposited before avulsion. Long-term observations show winter storms initiate scouring delta, contributing up 70% seabed erosion. then analyze 108 global deltas assess risks identify 17 facing similar situations decline storm intensification during past 40 years. Our findings suggest must be integrated into sustainability evaluations.