As UK temperatures soared to a record 40C in July 2022, the BBC analysed satellite data to reveal those living in deprived areas were more than twice as likely to be in places vulnerable to high heat levels.
The data analysis provided the basis for a news story and an interactive map that helped put people directly into the story of last year’s summer heat wave.
Satellite analytics company 4 Earth Intelligence (4EI), provided the data, which the BBC analysed.
As well as being used widely across BBC News outlets, the story was featured on the Apple News daily spotlight.
The Red Cross, plan to use the map as a tool to assist with future planning for heatwaves. It was also shared with the charity’s Community Resilience Team.
We used two levels of data for this story, postcode (zipcode) level to build the interactive map, and neighbourhood level (lower super output area or LSOA) data for the deprivation analysis.
4 Earth Intelligence used a statistical method published by academics to standardise land surface temperatures for each postcode and LSOA area, which involved combining satellite images for different dates over the past three years.
The temperature data was then adjusted to consider the different average temperatures of each region, to highlight hotter areas across the country, despite varying climates and temperatures.
A score, ranging from one to five, was then assigned to each postcode and LSOA. The score is an indicator of how likely it is that the area will experience high temperatures during hot weather, when compared with other areas in the surrounding neighbourhood.
The data team took the score for each LSOA area and cross-referenced it with the Index of Multiple Deprivation for each country, to establish if people living in more deprived areas were more vulnerable to high heat.
The design and development team took the postcode-level data and created an interactive map, allowing audiences to bring the story to their doorstep and make it more relevant to them.
Meanwhile, using the data our reporting team went to areas in England, Scotland and Wales experiencing high heat and high levels of deprivation to learn about the impacts this was having on people’s wellbeing. They gathered moving case studies of vulnerable people suffering in the heat, giving voice to those who struggle in heat waves each year.
This project was achieved through the use of R, QGIS, Zoomstack, Adobe XD, Photoshop and traditional broadcast reporting.
Context about the project:
The data was exclusively released to the BBC by 4 Earth Intelligence shortly after COP26, which had been held in Glasgow.
The granularity of the data was such that processing the data and boundaries for 1.8 million unique postcode files presented major technical challenges for our developers. They came up with an innovative solution not to use a vector map showing the heat scores/zones of each area, but to render the map as a series of image tiles. We layered the postcode polygons on top.
So, when a postcode was searched only the immediately relevant data was shown. This took the burden of rendering the map and all associated data away from the user, as it was handled by our servers.
What can other journalists learn from this project?
– It’s easy to forget satellite data can be used in ways beyond just mapping
– Not all stories are available in open data
– Don’t be daunted by projects involve large amounts of data, you don’t need to have all the answers when you start
– There can be large setbacks, but persistence, good planning and collaboration will help overcome these