Scholarlink

<p>Rapid-subsiding delta cities now face a dual threat: global sea-level rise (SLR) and local land subsidence (LSS). To achieve the UN’s Sustainable Development Goals (SDGs) on climate action and building resilient cities, it is crucial to understand the long-term driving mechanisms that amplify coastal flooding due to the combined effect of SLR and LSS to develop effective adaptation measures. Using Shanghai as an example, we combined climate-change projections and measured LSS with a calibrated 1D–2D numerical hydrodynamic model to simulate coastal flooding under varying human-activity intensities up to 2050 and 2100. Factor-decomposition analysis shows that anthropogenic actions—principally groundwater extraction and greenhouse gas emissions—raise the inundation areas of 200-year coastal flood hazards on average 3 times larger in Shanghai by 2100. When acting together, SLR and LSS amplify the 200-year flood extent by roughly 2 times more than the sum of their individual effects under high anthropogenic impact scenario (SSP5-8.5) by 2100. Within this high anthropogenic impact scenario, SLR drives the long-term hazard, with its share of inundated area rising from 8% in 2050 to 36% in 2100. In contrast, the influence of LSS is strongest in the near term, reaching up to 26% higher than that of SLR before 2050—before falling to 8% by 2100. Overtopping risks escalate markedly. By 2100, more than 78% of seawall segments and 53% of riverbanks are projected to be overtopped under 200-year flood. Notably, anthropogenic pressures increase riverbank failure far more (increase by 70% in overtopping volume) than seawall failure (only increase by 28%) compared to 2050 condition. These findings highlight the hidden threat of anthropogenic relative sea-level changes in exacerbating future coastal flooding of Shanghai. We emphasize the urgent need to restrict LSS immediately to limit short-term losses, while simultaneously planning for rising seas to secure long-term resilience. This dual approach offers viable pathway to meet the UN SDGs for rapidly urbanizing delta cities.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Anthropogenic stresses on sea-level rise and land subsidence triple the future coastal flooding in Shanghai

  • 期刊论文

  • 发表日期：

    2026年4月6日

查看全文
  • Kexin Yang,
  • Zhiguo Liu,
  • Min Zhang,
  • Jiahong Wen,
  • Linxia Xu,
  • Qing Zhan,
  • Yinpeng Li

摘要

Rapid-subsiding delta cities now face a dual threat: global sea-level rise (SLR) and local land subsidence (LSS). To achieve the UN’s Sustainable Development Goals (SDGs) on climate action and building resilient cities, it is crucial to understand the long-term driving mechanisms that amplify coastal flooding due to the combined effect of SLR and LSS to develop effective adaptation measures. Using Shanghai as an example, we combined climate-change projections and measured LSS with a calibrated 1D–2D numerical hydrodynamic model to simulate coastal flooding under varying human-activity intensities up to 2050 and 2100. Factor-decomposition analysis shows that anthropogenic actions—principally groundwater extraction and greenhouse gas emissions—raise the inundation areas of 200-year coastal flood hazards on average 3 times larger in Shanghai by 2100. When acting together, SLR and LSS amplify the 200-year flood extent by roughly 2 times more than the sum of their individual effects under high anthropogenic impact scenario (SSP5-8.5) by 2100. Within this high anthropogenic impact scenario, SLR drives the long-term hazard, with its share of inundated area rising from 8% in 2050 to 36% in 2100. In contrast, the influence of LSS is strongest in the near term, reaching up to 26% higher than that of SLR before 2050—before falling to 8% by 2100. Overtopping risks escalate markedly. By 2100, more than 78% of seawall segments and 53% of riverbanks are projected to be overtopped under 200-year flood. Notably, anthropogenic pressures increase riverbank failure far more (increase by 70% in overtopping volume) than seawall failure (only increase by 28%) compared to 2050 condition. These findings highlight the hidden threat of anthropogenic relative sea-level changes in exacerbating future coastal flooding of Shanghai. We emphasize the urgent need to restrict LSS immediately to limit short-term losses, while simultaneously planning for rising seas to secure long-term resilience. This dual approach offers viable pathway to meet the UN SDGs for rapidly urbanizing delta cities.

Graphical abstract