Rising water forces choices: how can we keep living in high-risk areas?
Climate change and growing cities are increasing the risk of flooding in many coastal regions. At the same time, governments and residents are investing in measures to reduce that risk, such as stronger houses and higher dikes. But when does the risk become so great that people decide to leave? And which form of urban development helps most to keep areas livable?
Climate scientist Lars Tierolf used computer models to answer these questions. He compared two forms of urbanization - densification (more housing within the existing city) and expansion (building on the outskirts) - and examined how households and governments respond to increasing flood danger.
His key findings:
- Both forms of urban growth increase flood risk, but which option is least risky varies by country. This means that tailored policy is needed for sustainable urban development.
- Households that reinforce their homes stay longer in high-risk areas. Encouraging such adaptations can therefore lead to less out-migration from coastal regions.
- Government measures have the greatest impact. Raising dikes can almost completely neutralize the negative effect of sea-level rise on people’s housing choices.
According to Tierolf, these insights can help policymakers make smart decisions about where and how we build. The research also shows that investments in climate adaptation—by both governments and residents—play a crucial role in keeping increasingly flood-prone areas livable.
More information on the thesis