London: Scientists have created a series of visualisations capturing urban heat island (UHI) effect during the recent heat wave in London. The simulation was done using data from Earth observation satellites and GIS software.
The UHI is caused mainly by the characteristics of materials used in construction of building and streets in the dense cityscape. The accumulation of heat is further increased by traffic pollution and the heat released from waste. Scientists from the University College London and Arup (a London-based consulting firm) used data provided by the UK Space Agency to capture the UHI effect in London. GIS technology helped them collate, analyse and visualise the complex remote sensing data. It created detailed maps capturing the differences in surface and air temperatures across Greater London. The images show clearly that there could be an up to 6°C difference between air and land temperatures of downtown areas and the rural suburbs. “During a heat wave, the Urban Heat Island effect prevents the city from cooling down at night, and means people aren’t able to escape the heat, especially in areas without many trees or green spaces,” said Polly Turton, senior technology consultant at Arup. “The UHI is clearly more of an issue in summer but this is likely to become more pronounced due to climate change,” she said. Knowing which parts of the city are heating up the most during spells of hot weather could help improve the urban planning and retrofitting of residential areas in the future.