---
title: "Define hazard, risk, vulnerability"
subject: "Engineering Geology II"
chapter: 5
key: "semester_4/engineering_geology_ii:hazard-risk-vulnerability"
source: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/hazard-risk-vulnerability
site: BCT Engineering
---

# Define hazard, risk, vulnerability

Engineering Geology II · Chapter 5: Geological Hazards

- Asked in: 2077 Chaitra, 3 marks; 2075 Bhadra, 1 marks (asked 2 times)
- Video: [Factors Affecting Hazard Risk](https://www.youtube.com/watch?v=1gxZrmqgXL8) — Rob Gamesby
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/engineering_geology_ii/hazard-risk-vulnerability
- Whole chapter: https://www.bctengineer.com/md/semester_4/engineering_geology_ii/chapter-5

## Question

Define hazard, risk and vulnerability (danger).

## Short answer

A hazard is a potentially damaging natural event. Vulnerability is the degree of loss (0–1) to exposed elements. Risk is expected loss, computed as Hazard × Vulnerability × Elements at risk.

## Answer

#### Hazard
A **hazard** is a potentially damaging natural or man-made event or phenomenon (such as earthquake, landslide, flood) that may cause loss of life, injury, property damage or environmental harm. It is described by its magnitude, location, frequency and probability.

#### Vulnerability (danger)
**Vulnerability** is the degree of loss or damage likely to occur to a given element (people, buildings, roads) when exposed to a hazard of given intensity. It is expressed from 0 (no loss) to 1 (total loss). It depends on construction quality, poverty, preparedness and location.

#### Risk
**Risk** is the expected loss (lives, injuries, property, economic activity) caused by a hazard in a given area and time. It combines the probability of the hazard, the elements at risk and their vulnerability.

$$
\text{Risk} = \text{Hazard} \times \text{Vulnerability} \times \text{Elements at risk}
$$

Example: a landslide on a steep slope is a hazard; the weak houses below are vulnerable; the possible loss of those houses and lives is the risk.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is vulnerability?
   A. The size of a landslide
   B. The speed of a flood
   C. Degree of loss to an exposed element from a hazard of given intensity
   D. The probability of an earthquake
   Answer: C. Vulnerability is expressed from 0 to 1. (Key point: Vulnerability)

2. What is the vulnerability value for total loss?
   A. 0
   B. 0.5
   C. 10
   D. 1
   Answer: D. 0 means no loss, 1 total loss. (Key point: Vulnerability range)

3. In the landslide example, what is the risk?
   A. Possible loss of the houses and lives below
   B. The steep slope
   C. The weak houses themselves
   D. The rainfall
   Answer: A. The slope is the hazard, houses are vulnerable, loss is the risk. (Key point: Example)

## Related in Engineering Geology II

- [Hazard versus risk](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Ahazard-vs-risk) — Engineering Geology II, chapter 5, asked 6×