G.4.2 Resilient City Design Notes

Managing Climatic and Geopolitical Risks

Climate Change Adaptation: Coastal vs. Inland Cities

Coastal Cities: Defending Against Rising Seas

1. Coastal cities are on the frontlines of climate change, requiring robust defenses against water-related risks:

• Hard Engineering Solutions: Sea walls, levees, and storm surge barriers protect against flooding.
• Soft Engineering Solutions: Restoring mangroves and wetlands provides natural buffers against storm surges.
• Managed Retreat: In extreme cases, relocating communities away from vulnerable areas may be necessary.

Inland Cities: Coping with Heat and Water Stress

1. Inland cities face different challenges, requiring tailored solutions:

• Urban Cooling Strategies: Planting trees, creating green roofs, and using reflective materials reduce the urban heat island effect.
• Water Management: Building reservoirs, improving irrigation efficiency, and recycling wastewater help address water scarcity.

Strategies for Managing Climatic Risks

Flood Defenses, Elevated Buildings, and Green Infrastructure

1. Flood Defenses: Cities like Rotterdam have invested in advanced flood defences to protect against rising sea levels and storm surges.

Example

Rotterdam, Netherlands: The Maeslantkering storm surge barrier is a marvel of engineering, designed to close automatically during extreme weather events. Additionally, the city has created water plazas, public spaces that double as water storage during heavy rainfall.

1. Elevated Buildings: In flood-prone areas, elevating buildings is a practical solution.

1. Green Infrastructure: Natural solutions like green roofs, permeable pavements, and urban wetlands help absorb rainwater and reduce flooding.

Example

Singapore's Bishan-Ang Mo Kio Park combines a naturalized river with recreational spaces, reducing flood risk while enhancing urban biodiversity.

Example

Sponge City

• This urban concept aims to enhance urban water management by using natural and engineered solutions to absorb, store, and release rainwater. The water is retained during intense precipitation decreasing the risk of flooding and gradually released later minimizing the risk of a drought.
• It involves creating green spaces, permeable surfaces, and water retention systems to reduce flooding, improve water quality, and replenish groundwater.
• One of the most well-known examples of a sponge city is Wuhan in China.

Disaster Preparedness Plans and Decentralized Energy Systems

1. Disaster Preparedness Plans: Effective plans include early warning systems, evacuation routes, and community education.

1. Decentralized Energy Systems: Relying on a single energy source makes cities vulnerable to disruptions.
2. Decentralized systems, such as solar panels and microgrids, enhance resilience.

Strategies for Managing Geopolitical Risks

Cybersecurity, Shelters and Decentralized Systems

1. Cybersecurity: As cities become more reliant on digital systems, protecting against cyberattacks is essential.

1. Shelters: Cities located in areas facing potential war invest in underground shelters.

Example

Helsinki, Finland has a vast network of underground bunkers and civil defense shelters, with over 5,500 shelters capable of housing nearly a million people, designed to protect against various threats, and some are used for public activities during peacetime.

1. Decentralized Systems: Reducing reliance on centralized infrastructure makes cities less vulnerable to attacks.