Declining vulnerability to river floods and the global benefits of adaptation

Proceedings of the National Academy of the Sciences (PNAS), April 20, 2015, published online before print, doi: 10.1073/pnas.1414439112:

This paper states that effective adaptation to the global impacts of river floods requires an in-depth understanding of the physical and socioeconomic drivers of risk. It addresses the knowledge gap in compelling evidence on spatiotemporal patterns in vulnerability of societies around the world, which impacts the understanding of the effects of vulnerability on global flood risk and the future projections of fatalities and losses available today.

The paper shows that trends and fluctuations in vulnerability to river floods around the world can be estimated by dynamic high-resolution modeling of flood hazard and exposure. The authors find that rising per-capita income coincided with a global decline in vulnerability between 1980 and 2010, which is reflected in decreasing mortality and losses as a share of the people and gross domestic product exposed to inundation. The results also demonstrate that vulnerability levels in low- and high-income countries have been converging, due to a relatively strong trend of vulnerability reduction in developing countries. Finally, the paper presents projections of flood losses and fatalities under 100 individual scenario and model combinations, and three possible global vulnerability scenarios. The projections emphasize that materialized flood risk largely results from human behavior and that future risk increases can be largely contained using effective disaster risk reduction strategies.