Saturday, January 23, 2010

Radical solutions to rising sea level threat

Lloyd’s: When Lloyd’s examined the threat posed by coastal flooding in its 360 Risk Insight Report Coastal Communities & Climate Change: Managing Future Insurability, a key finding was that society will need to be flexible enough to take account of the uncertainties surrounding rising sea levels. Now a forward thinking report released by the Royal Institute of British Architects’ (RIBA) think tank, Building Futures, and the Institution of Civil Engineers (ICE) has outlined three radical options: retreating inland, creating habitable defence structures and building out into the sea.

The report Facing up to Rising Sea Levels: Retreat, Defend, Attack? warns that the future of the UK’s coastal cities is in jeopardy due to rising sea levels, sinking landmasses and an increase in storm frequency. It argues that with over 12,000 km of coastline radical thinking is urgently needed to protect the UK’s at-risk communities from extreme flooding. Focusing on Kingston upon Hull and Portsmouth, two of the UK’s highest flood risk areas, the research presents six scenarios set up to 90 years in the future. The proposed solutions are breathtaking, but are based on realistic briefings.

One envisages Hull adopting a radical planning policy whereby the majority of the city of Hull retreats east and west, out of harm’s way. Under the scenario the old city, now an island, is defended as it is deemed to have significant assets and it is linked to the retreated community by several bridges. Compensation packages for the relocated community are part-funded by the savings made by not building and maintaining new flood defences. In 2080 the new settlement is branded New Hull, promoting tourism and investment.

In a similarly bold scenario for Portsmouth, two-tiered large piers emerge from the city, linking into existing infrastructure and providing residential, commercial and recreational spaces. The lower tiers are used for traffic. Existing buildings on the island are retro-fitted to adapt to the flood risk, and new developments are built with regular high levels of water in mind. This includes stilted and floating communities as seen in other countries.

The report’s authors argue that such solutions are realistic because hard engineering defences may not be sustainable or affordable in the future and because there is a growing deficit on flood defences that public funding is not covering….

An aerial view of Portsmouth, shot by Steff, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License

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