Lecture 16: Understanding vulnerability and risk

Question 1

Risk and its components

Answer 1

Risk = hazard interacts with a vulnerable human system.
Disaster = hazard affects a population/system without capacity to respond, cope, or recover.
* Hazard = potential damaging physical event, phenomenon, or activity.
* Vulnerability = degree to which a system or population is likely to suffer negative consequences from a hazard.
* Capacity = reduce disaster risks & increase resilience
* Resilience = ability to resist, absorb, accommodate, adapt to, and recover from hazard effects.

Question 2

Understanding vulnerability

Answer 2

• Social vulnerability: age, gender, ethnicity, social networks, governance.
• Physical vulnerability: housing quality, infrastructure access, remoteness.
• Economic vulnerability: assets, income stability, market access.
• Environmental vulnerability: reliance on rain‑fed agriculture, resource competition, land use change.
  Assessing Vulnerability in Data‐Scarce Contexts
• Constraints: outdated census (2014), limited hazard station coverage (<10 rain gauges over 10,000 km²).
• Remote sensing: land cover change, NDVI trends.
• Household surveys: purposive sampling in high-risk zones.
• Participatory vulnerability mapping: community workshops to identify local risk factors.

Question 3

Integrating human dimension

Answer 3

• Participatory mapping: delineated municipal wards, informal settlement extents.
• Hazard overlay: lava flow hazard zones (2002 flow lines + modeled inundation paths).
• Social Vulnerability Index (SVI): composite of 12 weighted variables: e.g., income, building type, mobility.
• Risk map: SVI x population density x hazard probability. Identifies seven high-risk wards, e.g., Karisimbi, Nyiragongo sectors.

Question 4

Risk calculation steps

Answer 4

1. Map hazard zones (proximal, medial, distal).
2. Geocode exposed assets (buildings, roads, utilities).
3. Assign vulnerability scores per asset type.
4. Multiply exposure x vulnerability x hazard likelihood.

Question 5

Dynamic Risk and Cascading Effects

Answer 5

Temporal dynamics:
* Diurnal population shifts (work vs. residential areas).
* Peak vulnerability when evening traffic coincides with lava flow arrival times.
Risk perception factors:
* Surveys show low trust in official alerts, reliance on community networks.
Cascading effects:
* Eruption can trigger fires, air quality issues, collapse of road networks, impeding evacuation.

Question 6

Disaster Risk Reduction (DRR)

Answer 6

= systematic approach to analyze and manage risk through prevention, mitigation, preparedness, and adaptation
Sendai Framework 2015–2030:
* Priority1: Understanding disaster risk.
* Priority2: Strengthening disaster risk governance.
* Priority3: Investing in disaster risk reduction for resilience.
* Priority4: Enhancing disaster preparedness and “Build Back Better.”
Global targets (7): reduce mortality, affected people, economic loss, infrastructure damage, enhance preparedness.
* Hazagora board game: teaches DRR concepts to youth.
* Volcano museum exhibitions: raise awareness on lava hazards.
* Chukuwa card game: engages communities in hazard-response planning.
DRR & Sustainable Development Goals (SDGs)
* Barriers to DRR: institutional fragmentation, limited funding, informal settlements in hazard zones.
Synergies with SDGs:
* SDG1 (No Poverty): risk reduction lowers disaster-induced poverty traps.
* SDG2 (Zero Hunger): protecting agricultural lands.
* SDG3 (Good Health): reducing disease outbreaks after disasters.
* SDG4 (Quality Education): integrating DRR into curricula.
* SDG11 (Sustainable Cities): land-use planning.
* SDG13 (Climate Action): adaptation measures.
Policy integration:
* Mainstream DRR in urban development plans.
* Allocate municipal budgets for hazard mitigation.
* Enforce building codes in high-risk wards.