{"id":132127,"date":"2023-10-09T07:57:08","date_gmt":"2023-10-09T06:57:08","guid":{"rendered":"https:\/\/www.pbctoday.co.uk\/news\/?p=132127"},"modified":"2023-10-09T09:38:30","modified_gmt":"2023-10-09T08:38:30","slug":"londons-most-exteme-urban-heat-island-4-5c-hotter-rural-areas","status":"publish","type":"post","link":"https:\/\/www.pbctoday.co.uk\/news\/digital-construction-news\/bim-news\/londons-most-exteme-urban-heat-island-4-5c-hotter-rural-areas\/132127\/","title":{"rendered":"London’s most extreme urban heat island 4.5\u00b0C hotter than rural areas, AI finds"},"content":{"rendered":"

A new heat modelling tool from Arup compared\u00a0extreme urban heat islands in six major cities, finding that a quarter of a million vulnerable Londoners live in the “hot spots”<\/h2>\n

A new urban heat modelling tool has found that London has the joint-fourth most extreme urban heat island (UHI) \u201chot spot\u201d of six major cities around the world, with temperatures 4.5\u00b0C hotter than rural surroundings.<\/p>\n

Arup\u2019s Urban Heat Snapshot mapped the most extreme hot spots in a 150km2 sample of the urban centres of Cairo, London, Los Angeles, Madrid, Mumbai and New York, using satellite images and AI.<\/p>\n

The findings bring to attention how the eradication of green spaces and excessive use of steel, glass and concrete in our cities have increased the impact of heat on different neighbourhoods- and how this could be reversed<\/a>.<\/p>\n

The data was taken from the hottest day in each of the cities in 2022<\/h3>\n\n\n\n\n\n\n\n\n\n
City and most severe UHI effect<\/strong><\/td>\nMost severe UHI Hot Spot location<\/strong><\/td>\nCoolest spot<\/strong><\/td>\nTemperature difference between hottest and coolest spot in the surveyed area<\/strong><\/td>\n<\/tr>\n
Madrid<\/strong>: UHI 8.5\u00b0C (Evening, 15\/06\/22)<\/td>\nPlaza Juan Pujol<\/strong>\u00a0(3% vegetation \/ 0% water)<\/td>\nThe North of Casa de Campo<\/strong> (89% vegetation \/ 0% water)<\/td>\n8\u00b0C<\/td>\n<\/tr>\n
Mumbai<\/strong>: UHI 7\u00b0C (Afternoon, 16\/03\/22)<\/td>\nGhatkopar East <\/strong>(39% vegetation \/ 0% water)<\/td>\nMaharashtra nature park<\/strong> (21% vegetation \/ 74% water)<\/td>\n8\u00b0C<\/td>\n<\/tr>\n
Cairo<\/strong>: UHI 5\u00b0C (Evening, 11\/06\/22)<\/td>\nBulaq Ad Daqrur<\/strong> (0% vegetation \/ 0% water)<\/td>\nSouth of Qorsaya Island (Pharaonic Village)\u00a0<\/strong>(28% vegetation \/ 30% water)<\/td>\n6 \u00b0C<\/td>\n<\/tr>\n
Los Angeles<\/strong>: UHI 5\u00b0C (Afternoon, 04\/09\/22)<\/td>\nWest Lake\u00a0<\/strong>(5% vegetation \/ 0% water)<\/td>\nE Debs Regional Park<\/strong>\u00a0(96% vegetation \/ 0% water)<\/td>\n5 \u00b0C<\/td>\n<\/tr>\n
London<\/strong>: UHI 4.5\u00b0C (Night, 19\/07\/22)<\/td>\nKilburn\/ South Hampstead<\/strong>\u00a0(38% vegetation \/ 0% water)<\/td>\nRegents Park\u00a0<\/strong>(89% vegetation \/ 1% water)<\/td>\n7\u00b0C<\/td>\n<\/tr>\n
New York<\/strong>: UHI 4.5\u00b0C (Afternoon, 09\/08\/22)<\/td>\nWashington Heights<\/strong> (3% vegetation \/ 0% water)<\/td>\nFerry Point Park area<\/strong> (77% vegetation \/ 1% water)<\/td>\n4.5\u00b0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

Arup\u2019s Urban Heat Snapshot builds on an advanced climate model by the University of Reading to demonstrate how advanced digital tools can bring academic models to real-word scenarios to find the causes of the UHI effect.<\/p>\n

It can then rapidly model solutions to show how the strategic deployment of nature and other interventions can help cities reduce the impact of hot spots.<\/p>\n

This method is much closer to people\u2019s actual experience than cruder satellite analysis of land surface temperatures, which can be skewed by the dramatic highs of heat-absorbing materials on roofs and roads.<\/p>\n

Cities are getting hotter due to climate change, with the number of cities exposed to extreme temperatures, 35\u00b0C and above, expected to triple by 2050.<\/p>\n

Extreme heat killed over 61,000 people in Europe<\/a> alone in 2022, one of the hottest years on record.<\/p>\n

Cities are not cooling in the night effectively either<\/h3>\n

It is increasingly understood that poorer neighbourhoods are also more at risk to heat exposure, due to factors such as a lack of trees and a lack of air conditioning.<\/p>\n

It was also found that three of the cities studied, including London, experienced the worst UHI \u201chot spots\u201d during the evening or night-time.<\/p>\n

Cement absorbs heat throughout the day and then slowly releases it after the sun sets, creating excessively warm nights that can bring stress and health issues. This can especially impact society’s most vulnerable, such as children, the elderly and the homeless.<\/p>\n

Within the study area in London, severe UHI \u201chot spots\u201d meant researchers found almost a quarter of a million elderly people and children are living in urban heat islands, with heat spikes of 4\u00b0C compared to rural surroundings. Studies suggest that the risk of death from excessively hot nights could increase to six times that of the current figures.<\/p>\n

Vegetation cover had a noticeable impact on urban temperatures<\/h3>\n

The coolest spots in cities were almost entirely found in parks away from residential and commercial areas and had over 70% vegetation cover from trees and other plants.<\/p>\n

The hottest spots in major cities had less than 6% vegetation cover with a significant impact, as seen in London, where the Kilburn and South Hampstead area, with 38% vegetation cover, experienced heat over 7\u00b0C hotter than Regent\u2019s Park, with 89% vegetation cover, a short distance away.<\/p>\n

Dima Zogheib, nature positive design lead at Arup, said: “We\u2019ve inadvertently designed many of our cities to be hot. We\u2019ve pushed out nature \u2013 concreted our streets, built high in steel and glass.\u00a0 And we\u2019ve largely confined our green spaces to grand parks, away from where most people live. Ponds, lakes, trees, grasses, soils and other surfaces that allow water to permeate into the ground have to be seen as vital infrastructure, essential to helping us adapt to climate change.<\/p>\n

“Our challenge as designers is to think creatively to strategically and equitably deploy nature throughout our cities. Today we have the advanced digital tools to help us<\/a> rapidly pinpoint where investment in solutions can make the greatest impact.\u201d<\/p>\n

Making rapid heat modelling available to the general public<\/h3>\n

Survey contributor Dr Ting Sun, UCL, Institute for Risk and Disaster Reduction, said: \u201cModelling urban heat has been the reserve of the few, mainly those in academia.<\/p>\n

“UHeat bridges this gap, drawing on the urban climate science and models developed by academia and combining them with increasing amount of city data available through remote sensing. It gives those on the ground shaping cities the tools they need to rapidly understand the impacts of their design on urban heat.\u201d<\/p>\n

The authors of the report recommended cities focus on:<\/h3>\n