Mapping Hot Spots Using Satellites to Prepare for UK Summer Heatwave

Bristol, UK, Earth observation company 4 Earth Intelligence has created a UK street level map of ‘at risk’ areas to help plan for and manage the effects of extreme hot weather conditions using satellites. Their Heat Hazard Postcode data is being made available free at the point of use to national organizations and multi-agency partnerships, such as Local Resilience Forums, that are currently battling the coronavirus pandemic.  Created with support from the Ordnance Survey through their Covid-19 Response licensing, the data is expected to be helpful in determining geographic areas experiencing extreme heat this summer.

Derived from satellite imagery and created using automated algorithms, the data identifies hot spots within urban areas where temperatures are generally higher forming an Urban Heat Island. Because of global warming, average temperatures forecasted for the summer of 2020 are already being predicted as one of the hottest on record, and it is expected to severely stress stretched public resources. In 2019 the heatwave resulted in almost 900 additional deaths in England. Experts predict that if the population is still in lockdown, that the figures for 2020 could be a lot higher.

Heatwaves historically can cause more fatalities. Increased daytime temperatures without evening cooling, plus higher air pollution levels associated with urban areas can affect human health by contributing to  respiratory difficulties, heat cramps and exhaustion. These conditions can also cause non-fatal heat stroke and heat-related mortality. The same sector of the population most susceptible to death from heatwaves are in the over 65 category – the same category most vulnerable to the Covid-19 virus.

4EI Exeter Heat Hazard Postcode Data

The way people may use this information might be as follows (according to company materials):

4EI: A Heat Hazard score ranging from 1 to 5 is provided for every postcode in Great Britain (5 referring to high heat hazard risk, 1 referring to low heat hazard risk). Each postcode can be queried to understand the likelihood that a significant heat event (i.e. a heat wave) will have a high impact. This can help to inform several things:

• Identification of ‘hot spot’ locations to target medical resources to hospitals which are likely to have an admission increase during heat waves;
• Understand which parts of the population are most at risk when a heat wave occurs;
• Understand where to plan and focus heat wave mitigation strategies (e.g. informing the population that they are at risk, and measures they can take to mitigate the risk);
• Support the creation of business continuity plans and corporate mitigation strategies, targeting of cooling products, identification of heat refuges and infrastructure protection;
• Support compliance with planning policies (e.g. understand which locations may be impacted by heat effects and where new developments may increase the local heat effect).

An Urban Heat Island or UHI is a metropolitan area that is warmer than the surrounding areas. Heat, created by energy from people, cars, transport and buildings’ heating, cooling and ventilation systems, interacts with materials used to construct city infrastructure that are good at insulating and retaining heat to create a ‘perfect storm’ of elevated temperatures. This can result in urban temperatures that are 3-4 degrees hotter than the surrounding non-urbanized areas.

Research funded by the Department of Health in the UK indicates that over 7,000 people could die from the effects of urban heat waves per year by the 2050s. The UHI effect can also impact air and water quality, and demands for energy, with implications for carbon neutral targets, public health, strategic planning and city resilience.

4EI Southeast England Heat Hazard Data

The 4EI Heat Hazard data will be supplied as CSV files for use in spreadsheets so that end users who are not used to working with geospatial data can easily access the data and will be available for use until the end of September 2020.

Additional comments by Richard Flemmings, CTO and co-founder of 4EI are as follows:

Does the heat hazard map already show what areas of the country will be most affected by the heat wave and what areas are those?

Yes, as one would expect it is in the urban areas, but the impact can vary within the urban landscape. Areas with blue and green infrastructure are typically less effected (close to parks, lakes and water courses), as they benefit from a natural cooling effect when compared to man-made infrastructure.

The data was derived from satellite imagery captured over the summers of 2017 to 2019. Automated algorithms were used to produce information on land surface temperature. Further processing allowed the data to be standardized across different locations and then was statistically analyzed to show the location of heat anomalies throughout Great Britain. Heat anomalies were then split into five categories, demonstrating the tendency of different locations to reach higher temperatures.

Would this also be useful to insurance companies who want to identify prime real estate areas?

Yes, if they want to look at Carbon zero (air conditioning increases energy use) and property desirability. It is also of interest to developers to understand what measures they need to apply in terms of ventilation, and planners to assess what policies should be applied and what sites should be approved.

What are the automated algorithms providing along with the satellite imagery from the three past years?

Those are algorithms developed by 4EI using best available earth observation scientific knowledge.

How do you expect agencies to be able to use the post code data from the heat hazard map to save lives?

They will be essentially using complex EO science distilled to a simple and useable form for the end user. Most people can use spreadsheets and understand postcodes. They can quickly understand where there are potential impact areas and can use low tech approaches such as letter drops and door to door notification if appropriate. They can also match to their own vulnerable population datasets by using the postcode field for very targeted approaches.

What are the five categories the heat anomalies were broken into to show the higher temperatures in different locations?

Satellite data has been statistically analyzed to rank each location on a scale of 1 to 5, with 1 showing previous heat events of having a low impact, and 5 showing previous heat events of having a high impact on surface temperature vs the surrounding area.

By providing Category 1 responders with intelligence derived from past events we hope that this will help plan for and mitigate against the worst scenario. This information can be used to target vulnerable households with information about coping strategies and signpost supporting organizations or emergency responders.

 For more information visit  4 Earth Intelligence FAQs

Tags: climate change, cloud, data, imagery, location, mapping, maps, remote sensing, satellite imagery

Categories: analytics, climate change, data, drones, emergency response, field GIS, geospatial, GIS, government, mapping, public safety, remote sensing, satellite imagery

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