Resilent City Design (SL IB Geography)

What is urban resilience?

• Resilience is defined as:

The ability to recover and rebound from challenges and setbacks

• Urban resilience is how well the communities, businesses, population and systems in a city are able to function and be economically productive, no matter the issues faced
• Although similar to sustainability, it focuses on:
  • Chronic stresses such as water and transport infrastructure
  • Shock events such as flooding or terrorism

Why are cities vulnerable?

• The larger cities become and the higher the population densities, the more vulnerable they are
  • The UN estimates that 3 out of every 5 cities with a population over 500 000 are vulnerable to natural hazards
  • Some cities, such as Manila and Tokyo, are vulnerable to up to five natural hazards
  • There are only three of the world's megacities which are at low risk or no risk of natural hazards
• Urban areas are centres of population and economic activity
• When natural hazards affect urban areas, the effects are frequently more severe and expensive
• Climate change is increasing the vulnerability of cities due to the increase in frequency and severity of flooding, drought and tropical cyclones
• To be able to withstand these hazards, cities need to be resilient

Measuring resilience

• The Organisation for Economic Co-operation and Development (OECD) states there are four components of resilience:
  • Economic 
  • Social
  • Environmental
  • Governance
• These can be assessed using the following criteria:

Criteria to Assess Resilience

Resilient city design

• There are many ways in which resilience can be incorporated into urban planning, city and building design including:
  • Infrastructure improvements and resilience
  • Urban heat reduction
  • Energy efficiency
  • Creation of green spaces
  • Emergency preparedness
  • Flood mitigation
• In cities which are vulnerable to tectonic hazards, there are several mitigations which may be put in place, including:
  • Improved planning and building regulations
  • Earthquake-resistant building design
  • Land use zoning to ensure vital infrastructure and buildings are not in the most vulnerable areas
  • Education to make the population aware of the actions to take before, during and after an event
  • Hazard mapping to identify the most vulnerable areas

• Climate change brings additional risks to urban areas
• Many cities are located on coastlines and floodplains which are high-risk locations
• Climatic risks include:
  • Flooding
  • Storms
  • Water-borne diseases
  • Heatwaves
  • Wildfires
  • Drought

Managing climatic risks

• Many cities are now integrating planning and building design to mitigate these risks 
• In Mexico City, water supply issues caused by drought mean that 40% of the population lacks access to regular water supplies
  • The city now has a goal of installing 10 000 rainwater harvesting systems each year in households across the city
• In Melbourne, Australia, there have been increases in:
  • Stormwater harvesting to irrigate parks
  • Investment in green space to provide shade and enhance biodiversity
  • Permeable surfaces to reduce flooding risk
• Many parts of The Netherlands are at risk of flooding. Rotterdam's strategies include:
  • Building design to cope with flooding and sea level rise 
  • Plans for a floating neighbourhood, which will have homes, offices, a school and a park
  • Water squares, which are areas set lower than the surroundings, can fill with and store water 
  • Increased green spaces and permeable surfaces to allow water to infiltrate
  • Working with residents to adapt housing by:
    • Moving wiring to upper floors 
    • Replacing wooden floors with more water-resistant coverings
    • Subsidising green roofs
    • Collection of rainwater

• Geopolitics are politics which are influenced by geographical factors, including:
  • Level of development
  • Resource availability
  • Land ownership
• The main geopolitical threats to urban areas include:
  • War
  • Terrorism
  • Protests
  • Segregation of communities
  • Loss of economic power

Managing geopolitical risks

• Increased threat of terrorism and protests have led many cities to implement strategies to reduce these risks
• In London, UK, some of the strategies which have been implemented include:
  • External barriers to prevent vehicles from ramming buildings or infrastructure
  • Improved building materials which are blast-resistant
  • Better communications system
  • CCTV 
  • Increased security measures for people entering public buildings