揭示全球河流三角洲人口面临的洪涝脆弱性 | 《自然-通讯》论文

论文标题：Coastal flooding will disproportionately impact people on river deltas

期刊：Nature Communications

作者：Douglas A. Edmonds, Rebecca L. Caldwell et.al

发表时间：2020/09/29

数字识别码：10.1038/s41467-020-18531-4

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根据《自然-通讯》发表的一项研究Coastal flooding will disproportionately impact people on river deltas，2017年全球有3.39亿人口居住在河流三角洲，其中89%的人口所居住的三角洲和大部分热带气旋活动处于相同的维度区域。鉴于未来沿海洪涝可能恶化，论文总结认为洪涝将对居住在河流三角洲的人口造成不成比例的影响，尤其是在发展中经济体和最不发达经济体。

河流三角洲由于海拔低，尤其易受沿海洪涝影响。此外，预计到本世纪末，热带气旋等事件将变得更加强烈。但是，居住在这些地区的人口的数量及其洪涝脆弱性却未可知，这妨碍了相关的减灾规划。

美国印第安纳大学的Douglas Edmonds及同事开发了一个包含2174个三角洲区域的全球数据集，用以确定居住在这些区域的人口数量及其洪涝脆弱性。作者发现2017年有3.39亿人居住在三角洲，其中3.29亿人来自发展中经济体或最不发达经济体。据估计，全球有7600万人居住的地区暴露在热带气旋所导致的洪涝风险下，作者的分析提示其中41%（即3100万）居住在河流三角洲，而这其中的92%（即2800万）生活在发展中经济体或最不发达经济体，这些地方缺少减灾所需的基础设施。

全球三角洲的区域和人口分布图 | 来源：Edmonds et al.

摘要：Climate change is intensifying tropical cyclones, accelerating sea-level rise, and increasing coastal flooding. River deltas are especially vulnerable to flooding because of their low elevations and densely populated cities. Yet, we do not know how many people live on deltas and their exposure to flooding. Using a new global dataset, we show that 339 million people lived on river deltas in 2017 and 89% of those people live in the same latitudinal zone as most tropical cyclone activity. We calculate that 41% (31 million) of the global population exposed to tropical cyclone flooding live on deltas, with 92% (28 million) in developing or least developed economies. Furthermore, 80% (25 million) live on sediment-starved deltas, which cannot naturally mitigate flooding through sediment deposition. Given that coastal flooding will only worsen, we must reframe this problem as one that will disproportionately impact people on river deltas, particularly in developing and least-developed economies.