1. 1 Challenge the future The adaptive delta metropolis: Gradual adaptation or system interventions? Han Meyer, Bas Jonkman

2. 2 Challenge the future Global background Rapid economic development in flood-prone areas Sea level rise and subsidence Frequent floods in developed and developing countries Recent Worldbank study on coastal flood risks (Hallegatte et al., 2013): Current Risks in coastal cities US$ 6 billion per year 2050: US $52 billion per year (!?) R. Waterman Maeslant barrier

3. 3 Challenge the future Strategies for coastal regions Estuaries / bays: Dikes Dams Storm surge barrier Strategy / solution: Driven by societal needs Effects on various functions DIMI seminar April 10, 2015 “”next generation storm surge barriers”

4. 4 Challenge the future Map by Nijhuis & Pouderoijen, 2013

5. 5 Challenge the future http://wallpapers.brothersoft.com/maeslantkering-107665-1920x1200.html

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7. 7 Perspectives on adaptation of deltas Source: Meyer, Nillesen, Zonneveld 2012 Architecture

8. 8 Challenge the future Perspectives on adaptation of deltas Technology, Policy and Management Source: Haasnoot et al. https://www.deltares.nl/en/adaptive-pathways/

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10. 10 Challenge the future 10 Texas: Coastal spine Challenge the future Houston Galveston

11. 11 Challenge the future Challenges in delta planning Future developments: Demand for safety Economic and urban growth (?) Changes in the energy supply and port structure? Sea level rise Interventions Gradual adaptation over time Or large-scale system interventions Effects of interventions: safety, economy, ecology, etc. Interdependence between interventions and development

12. 12 Challenge the future Program 13.30 Bas Jonkman (TU-Delft) Introduction 13.40 Harold van Waveren (Rijkswaterstaat) - Open or closed river mouth in the Rotterdam region 14.00 Gijs van Zonneveld (WWF) The river as a tidal park 14.20 Bas Jonkman The case Houston – Galveston Bay 14.40 Discussion by moderator Han Meyer 15.15 Closure

13. 13 Challenge the future Homework + Link to plenary session Derive one or more messages / propositions from this session “Take home message” to a broader audience To be identified during closing discussion

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19. 19 Challenge the future Effects of regional scale interventions to local scale conditions Source: Meyer, Nillesen, Zonneveld 2012