Deltares, Inland Water Systems Unit, P.O. Box 177, Delft, The Netherlands.
NUS Environmental Research Institute (NERI), National University of Singapore, 1 Engineering Drive, Singapore, Singapore.
Nat Commun. 2021 Jun 29;12(1):3592. doi: 10.1038/s41467-021-23810-9.
Coastal flood risk assessments require accurate land elevation data. Those to date existed only for limited parts of the world, which has resulted in high uncertainty in projections of land area at risk of sea-level rise (SLR). Here we have applied the first global elevation model derived from satellite LiDAR data. We find that of the worldwide land area less than 2 m above mean sea level, that is most vulnerable to SLR, 649,000 km or 62% is in the tropics. Even assuming a low-end relative SLR of 1 m by 2100 and a stable lowland population number and distribution, the 2020 population of 267 million on such land would increase to at least 410 million of which 72% in the tropics and 59% in tropical Asia alone. We conclude that the burden of current coastal flood risk and future SLR falls disproportionally on tropical regions, especially in Asia.
沿海洪灾风险评估需要准确的陆地高程数据。迄今为止，这些数据仅存在于世界的有限地区，这导致海平面上升（SLR）风险地区的预测存在高度不确定性。在这里，我们应用了第一个基于卫星激光雷达数据的全球高程模型。我们发现，在全球范围内，海拔低于平均海平面 2 米以下的、最容易受到 SLR 影响的陆地面积中，有 649,000 平方公里或 62%位于热带地区。即使假设到 2100 年相对海平面上升低至 1 米，并且低地人口数量和分布保持稳定，那么在这样的土地上现有的 2.67 亿人口将至少增加到 4.1 亿，其中 72%位于热带地区，仅在热带亚洲就占 59%。我们的结论是，当前沿海洪灾风险和未来 SLR 的负担不成比例地落在热带地区，尤其是亚洲。
