Declining vulnerability to river floods and the global benefits of adaptation

TLDR

Understanding the vulnerability of societies around the world is crucial for understanding historical trends in flood risk and for producing accurate projections of fatalities and losses. We reproduced historical river flood occurrence using daily climate data for 1980–2010 and quantified the natural and socioeconomic contributions to flood risk trends. The study finds that as income rises, fatalities and losses relative to exposed population and GDP decline, vulnerability levels converge between low‑ and high‑income countries, and that enhanced adaptation can largely contain future flood losses under a range of climate and socioeconomic scenarios.

Abstract

Significance Understanding the vulnerability of societies around the world is crucial for understanding historical trends in flood risk and for producing accurate projections of fatalities and losses. We reproduced historical river flood occurrence using daily climate data for the period 1980–2010 and quantified the natural and socioeconomic contributions to flood risk trends. We show that the fatalities and losses as a share of the exposed population and gross domestic product are decreasing with rising income. We also show that there is a tendency of convergence in vulnerability levels between low- and high-income countries. Projections based on a wide range of climate change and socioeconomic development scenarios demonstrate that amplified adaptation efforts have the potential to largely contain losses from future floods.