Methodology

The explorer follows the IPCC risk framing: risk arises from the interaction of hazard, exposure and vulnerability, where vulnerability is sensitivity moderated by adaptive capacity.

Domains

Hazard

Climate-related hazards, currently flood and heat.

Exposure

People, homes and assets located where hazards occur.

Sensitivity

Characteristics of people that increase sensitivity to harm.

Adaptive capacity

Resources that help communities prepare, respond and recover.

1. Min-max normalisation

Each indicator is rescaled to 0–1 across all CCR LSOAs. Direction is then applied: for −1 indicators the scale is reversed, so a higher score always means more of the domain. Adaptive capacity is oriented so that higher means more capacity.

nᵢ = (xᵢ − min) / (max − min); if direction = −1: nᵢ = 1 − nᵢ

2. Domain scores

A domain score is the weighted mean of the normalised indicators in that domain. Only indicators with values for at least 80% of CCR LSOAs are used.

D = Σ(wᵢ · nᵢ) / Σwᵢ for indicators i in the domain with ≥ 80% coverage

3. Hazard-specific composite

Separate composites are built for flood and heat. A composite is only produced if every domain has at least one indicator with at least 80% coverage; otherwise it shows “Insufficient data” and names the missing domain.

Composite(hazard) = H × E × (S × (1 − AC))

Where

xᵢ is the raw value of indicator i, wᵢ its weight
H is the hazard score for the chosen hazard, E exposure, S sensitivity
AC is the adaptive capacity score (0–1, higher = more capacity)

Scores are relative rankings within the Cardiff Capital Region, not absolute measures of risk.

Evidence grade of a score

A score inherits the lowest grade of the indicators used to compute it (C is lower than B, B lower than A).

Assumptions

AssumptionPrivate renting — A higher share of households renting privately is treated as lower adaptive capacity, because tenants have limited control over changes to the home. This is a working assumption, not an established finding.
AssumptionWIMD 2019 on 2021 areas — WIMD 2019 ranks are published for 2011 LSOAs. Unchanged and split areas take their 2011 rank directly; merged areas take the population-weighted mean of their parents' ranks and are graded C (derived).
AssumptionFlood hazard — Flood hazard is the share of an LSOA's area inside an NRW Flood Risk Assessment Wales High or Medium risk zone. It describes land area, not the number of homes at risk.

Future scenarios

Scenario views apply UKCP18 projections to hazard indicators. They are labelled “Illustrative, based on UKCP18” and are not forecasts.

Limitations

Rankings are relative to the CCR and change if the set of areas changes.
Percentiles hide the size of differences between areas.
LSOA averages may mask variation within an area.