Mapping vulnerability to climate-related hazards to inform local authority action

Local authorities play a vital role in building resilience to the health impacts of climate change. In this study, researchers including Fathom’s Professor Jeff Neal, worked with a local authority to develop a tool that would help identify communities most vulnerable to climate-related hazard.

The UK government’s most recent country-wide Climate Change Risk Assessment, published in 2022, defines the risk from flooding and heatwaves in the UK as “very high”.

The impacts of these climate-related hazards are adversely affecting people’s health. The UK’s heatwaves of 2022, for example, have been linked to 3,271 more deaths than the five-year average.

Flooding, meanwhile, not only poses an immediate threat to life but can also have a severe impact on mental health and wellbeing in the longer term.

The challenge for local authorities

Local authorities in the UK play a crucial role in building community resilience to the health impacts of a changing climate. But they face huge challenges in prioritizing long-term strategies, such as climate change adaptation, because their resources are limited.

While the tools exist to assess exposure to hazard, local authorities need more technical support and cross-system collaboration to use them effectively and to translate risk assessments into action.

For this study, researchers worked closely with South Gloucestershire Council to explore what is needed to help them deal local authorities with climate-related health risk more effectively.

Using these insights, they then co-developed and trialled a vulnerability mapping tool to help identify the communities, population groups and areas most at risk.

The research

South Gloucestershire Council (SGC) was chosen for the study because it has been active in climate adaptation since it declared a climate emergency in 2019. The county is also located in the southwest of England – the region with the highest projected changes in flooding and heat hazard in the UK.

Stakeholder engagement

Through one-to-one discussions and group workshops, the participants identified flooding and heatwaves as the priorities for the study, and they explored what kind of information would be the most useful in a high-level map of vulnerability to climate hazards.

The main concern was a lack of data to identify areas where vulnerability and climate hazard exposure overlap. Three core themes emerged:

• Community engagement: Accessible, visual data can support stronger collaboration with communities, helping them understand local climate risks and take informed action.
• Health inequality reduction: More data is needed to reveal how climate change affects different groups, enabling targeted, equitable interventions aligned with broader health priorities.
• Future planning and collaboration: Stakeholders want better cross-sector coordination and tools to support joint planning. Improved data could help overcome budget constraints and guide decision-making.

Vulnerability mapping tool

The researchers and study participants used the knowledge gained during the stakeholder engagement exercises to develop a vulnerability mapping tool – a proof-of-concept (POC) application that will later be trialled with the same local authority.

The team first created a vulnerability index using publicly available census data, including 33 metrics under four main categories: adaptive capacity, health, sensitivity and living environment. This was then overlaid with flood data from Fathom and heat data from the UK met office to determine hazard exposure.

The aim of the tool is to help identify vulnerable populations, understand their exposure risks and ultimately to support more granular decision-making at the local authority level.

Conclusion

The potential uses of this tool were explored with the local authority, to more deeply understand where public health intelligence can add value in planning, education and training, and community engagement processes. 

A pilot study was planned to assess the tool’s practical value and potential for wider use. By promoting collaboration and highlighting co-benefits of adaptation, the tool aims to support health equity and a more ‘just transition’.