Urban land pattern may hold key to reduce exposure to weather extremes

NEW DELHI: How a city is laid out, called urban land pattern, may help in reducing population exposure to future weather extremes, scientists in the US have found.

The design of urban landscape – how buildings are spread out, clustered or dispersed – and how it fits into the surrounding environment, seems to matter more than simply the size of a city, the researchers from the universities from Delaware and Wyoming have found.

The researchers investigated how changes in urban land and population will affect future populations' exposures to weather extremes under climate conditions at the end of the 21st century.

"Regardless of the size of a city, well planned urban land patterns can reduce population exposures to weather extremes," said researcher Jing Gao, an assistant professor at the College of Earth, Ocean and Environment in Delaware.

"In other words, cities large and small can reduce their risks caused by weather extremes by better arranging their land developments," said Gao. The researchers said that the findings encourage researchers and practitioners to reconsider how cities are designed and built, in order to be in harmony with their natural surroundings and more resilient to climate risks.

Their study is published in the journal Nature Communications. These findings differ from current common perceptions. For example, existing literature in this area has almost exclusively focused on limiting the amount of urban land development, Gao said.

For the study, the researchers looked at urban areas across the continental US, including cities large and small, with various development densities and in different climate regions. Then, they predicted how the urban areas will grow by 2100 on the basis of development data of the past 40 years.

The team analysed how these urban land changes might affect weather extremes, such as heat and cold waves, heavy rainfall and severe thunderstorms, and the number of people potentially exposed to these events at the end of the century under varied climate and urban development conditions.

"Carefully designed urban land patterns cannot completely erase increased population exposures to weather extremes resulting from climate change, but it can generate a meaningful reduction of the increase in risks," said Gao. And the cost to start is small, Gao said. No extravagant measure, such as leveling and rebuilding a large area at once, is required.

"Instead, when building new and renovating existing parts of a city, we should adjust our mindset to consider how the new development and renovation will change the way the city as a whole situates in its natural surroundings, and how the city and its surrounds can be one integrated human-environment system at large scales over the long run," Gao said. "The key is to start adjusting how we think about development now."