Risk and resilience Notes

How Can Risk Be Separated Into Hazards, Exposure, and Vulnerability?

1. A hazard is a potentially damaging event or process, for example a flood, heatwave, earthquake, pandemic, or an economic recession.
2. Hazards can be sudden (earthquake) or slow-moving (sea-level rise, long-term drought, rising housing costs).
3. Exposure refers to what is in harm's way: people, homes, transport links, hospitals, businesses, and key infrastructure.
4. Exposure increases when cities expand into floodplains, steep slopes, or coastal zones, or when essential services are clustered in one location.
5. Vulnerability describes how severely exposed people or systems would be affected.

Why Is Resilience More Than Just "Bouncing Back"?

1. Resilience is often explained as the ability to "bounce back," but human and urban resilience also includes longer-term change.
2. A resilient city or community can:
   1. Absorb a shock with limited disruption (for example, parks designed to temporarily store floodwater).
   2. Recover quickly (restoring transport, schools, healthcare, and communications).
   3. Adapt to reduce future risk (improving drainage standards, updating land-use rules).
   4. Transform when the existing system is unsafe or unfair (redesigning transport to reduce air pollution and dependence on cars).

How Does Innovation Reduce Risk?

1. Cities often rely on innovation to increase sustainability and resilience: renewable energy, energy-efficient buildings, smart traffic systems, flood-warning sensors, and improved waste management.
2. These can reduce risk by improving efficiency, monitoring, and early warning.
3. However, innovation can also introduce new problems:
   1. Greater dependence on complex technology can create single points of failure.
   2. Benefits may be uneven, widening inequality if only wealthier residents can access improvements.
   3. Smart city technologies raise concerns about privacy, accountability, and who controls data.

Case study

The 2021 German Floods

• In July 2021, massive floods struck Western Germany killing at least 196 people.
• At the time, the government relied on smartphone apps (like NINA and Katwarn) and TV broadcasts to warn residents.
• This was problematic because:
  • Infrastructure
    • The floodwaters knocked out power and cell towers early on.
    • If you had no signal or your battery died, you received zero warnings.
  • Demographics
    • Many elderly victims did not own smartphones or know how to use these specific apps.
  • The "Silent" Disaster
    • Because Germany had dismantled thousands of "Cold War era" air-raid sirens to save money, there was no loud, analog alarm to wake people up at night.
  • The Resilient Shift
    • Following the 180+ deaths, Germany admitted the reliance on digital tech was a point of failure.
    • They began a nationwide program to reinstall physical sirens and introduce "Cell Broadcast" technology (alerts that work like radio signals and don't require an app or data plan) to ensure the warning reaches everyone, not just the tech-savvy.

What's The Best Way To Use Evidence To Think Critically About Data?

1. Risk and resilience arguments often use evidence such as flood frequency, temperature trends, air pollution levels, commute times, unemployment rates, or housing costs.
2. Two common ways data is presented are:
   1. Time series data (change over time), for example monthly inflation or annual average temperature.
   2. Scatter plots (relationship between two variables), for example income versus life expectancy.
3. Two variables may move together by coincidence, or because both are influenced by another factor.