Methodology
Scoring follows the DHSUD CDRA framework, version DHSUD-2025.1. The tables below are the published ones; every value in this assessment is derived from them and from nothing else.
severity of consequence = (exposure + vulnerability) / 2
risk score = likelihood x severity of consequence
Adaptive capacity is inverted: A is the strongest and scores 1. The severity table published by DHSUD is reproduced exactly by the formula above at all sixteen cells, which the test suite asserts cell by cell.
Exposure
| Score | Rating | Range |
|---|---|---|
| 4 | Very high | >15% affected |
| 3 | High | 11-15% affected |
| 2 | Moderate | 6-10% affected |
| 1 | Low | 0-5% affected |
Sensitivity
| Score | Rating | Range |
|---|---|---|
| 4 | Very high | >15% sensitive |
| 3 | High | 11-15% sensitive |
| 2 | Moderate | 6-10% sensitive |
| 1 | Low | 0-5% sensitive |
Adaptive capacity
Inverted deliberately: A scores 1 and is the strongest capacity, because the score feeds a vulnerability index in which a higher number always means worse.
| Code | Score | Rating | Description |
|---|---|---|---|
| A | 1 | Very high | Local government is implementing existing regulations on hazard mitigation and structural design and monitors compliance thereof |
| B | 2 | High | Local government is implementing existing regulations on hazard mitigation and structural design |
| C | 3 | Moderate | Local government has existing regulations on hazard mitigation and structural design |
| D | 4 | Low | Local government has no regulations on hazard mitigation and structural design |
Severity of consequence
| Vuln 1 | Vuln 2 | Vuln 3 | Vuln 4 | |
|---|---|---|---|---|
| Exposure 4 | 2.50 | 3.00 | 3.50 | 4.00 |
| Exposure 3 | 2.00 | 2.50 | 3.00 | 3.50 |
| Exposure 2 | 1.50 | 2.00 | 2.50 | 3.00 |
| Exposure 1 | 1.00 | 1.50 | 2.00 | 2.50 |
Risk categories and land-use control
| Category | Risk score | Land-use control |
|---|---|---|
| Very High-Risk Areas | 12 – 16 | Prohibited |
| High Risk Areas | 7 – 11.99 | Discretionary |
| Moderate Risk Areas | 3 – 6.99 | Conditional |
| Low Risk Areas | 1 – 2.99 | Permitted |