Hazard Vulnerability Analysis
Definition
Hazard vulnerability analysis evaluates how susceptible people, infrastructure, and ecosystems are to harm when hazards occur. It combines hazard intensity with exposure and the capacity to anticipate, cope, and recover. In GIS, analysts overlay hazard layers with building inventories, demographics, critical facilities, and social indicators like age, disability, household income, or car ownership. The result is not a single map but a suite of indicators that reveal who is likely to be hit hardest and why. Transparent methods and participatory validation are essential, since vulnerability is shaped by history and policy, not just geography.
Application
Cities use vulnerability analyses to prioritize retrofits, cooling centers, evacuation assistance lists, and resilient infrastructure. Public health departments plan outreach to medically fragile residents during heat waves or power outages. Donors and NGOs select neighborhoods for early warning systems and risk communication tailored to local languages and culture. The analysis also informs equitable recovery by identifying groups that may need extra support after disasters.
FAQ
What is the difference between exposure and vulnerability?
Exposure is what is in harm’s way. Vulnerability describes the sensitivity and capacity of those exposed to suffer damage and to recover. Two places with the same hazard and exposure can have different outcomes because of vulnerability.
How can we avoid stigmatizing communities with vulnerability maps?
Engage residents, emphasize strengths and assets, publish context and action plans, and avoid using maps to justify disinvestment. Maps should enable support, not blame.
Which indicators are most useful across hazards?
Age, disability, mobility access, housing quality, language isolation, and income consistently shape outcomes. Locally specific factors such as basement apartments or informal work may also matter.
How should composite indices be validated?
Compare against observed impacts from past events, run sensitivity tests, and invite expert and community review. Provide open documentation so others can reproduce the results.