Flood-risk reduction: structural measures and diverse strategies

Floods continue to hit many countries, both less developed and industrialized, bringing human suffering and immense economic damage (see floodobservatory.colorado.edu/). Hurricane Florence and Typhoon Mangkhut were just the most recent reminders of the disruption that flooding can bring. Hence, striving to improve the flood-risk governance system has broad relevance. Yet, the reduction of flood risk, understood globally as a combination of hazard, exposure, and vulnerability, is a rather distant goal (Fig. 1).Fig. 1. In January 2018, the Seine flooded in Paris. When it comes to flood policies around the world, both social and engineering factors must be further explored and scrutinized—as should notions of justice as they relate to flooding impacts and responses. Image courtesy of Shutterstock.com/Ekaterina Pokrovsky.Several weaknesses of flood-risk management in the United States, recognized in a recent PNAS Opinion (1), generally apply to many European countries as well, despite all the political, economic, and social differences between the United States and Europe. From our European perspective, this panoply of approaches suggests that both social and engineering factors must be further explored and scrutinized across the globe—as should notions of justice related to flooding impacts and responses.The European Union (EU) has dedicated legislation, called Directive 2007/60/EC, on the assessment and management of flood risks (2). This “Floods Directive” aims to reduce and manage the risks that floods pose to human health, economic activity, the environment, and cultural heritage. The Directive requires all 28 EU Member States to identify areas at risk of flooding, to map the flood extent as well as assets and humans at risk in these areas, and to take adequate measures to reduce this flood risk. The Directive takes a procedural approach and allows EU Member States policy discretion in designing flood-risk management. The Directive, as well as national obligations related to it, … ↵1To whom correspondence should be addressed. Email: kundzewicz{at}yahoo.com.