UNIVERSITY OF TEXAS IN AUSTIN
When it comes to extreme weather, climate change often gets everyone’s attention. But according to a study from the University of Texas at Austin and two universities in China, the unique effects of cities – which can intensify hurricanes and affect where rain falls – also need to be accounted for. arrive.
Dev Niyogi, a professor at the UT Jackson School of Geosciences and the Cockrell School of Engineering, said: “In addition to cutting emissions, we need to recognize that understanding the effects of urbanization is part of it. of solution.
Niyogi is a co-author of a study published in Geophysical research letter used computer models to investigate how cities and climate change affect the rainfall that hit the Rotterdam-Brussels-Cologne metropolitan area on July 14, 2021.
The model shows that the interplay of large-scale climate and local-scale urbanization has increased storm intensity, causing more rainfall than climate or urbanization.
The severe weather system was part of a storm complex that brought heavy rain across Western Europe in the summer of 2021, causing devastating and deadly flooding that killed at least 242 people, making it one of Deadliest floods in European history.
The research team also includes scientists from Nanjing University and Tsinghua University.
Urbanization is known to impact local climates and intensify hurricanes. City buildings are taller and closer together, which can block storm systems while directing them away from the city center. And the relatively warmer temperatures of cities and higher pollution levels can often increase humidity in clouds.
In the new study, the researchers found that the interaction between a warmer climate and a city environment concentrates rainstorms in suburban areas and increases rainfall by 50% when compared to city’s own influence. That means of the nearly 6 inches of rain that fell in the metropolitan area on July 14, about 3 inches of that could be attributed to these interactions.
To conduct the study, the scientists created a hurricane computer model that included environmental, city and climate impacts. The model of the storm proved to be representative of the actual event. The storm centered on the same areas in eastern Belgium and western Germany and took place in the same timeline as the simulation ran from July 13 to 17 with the heaviest rainfall falling on July 14. The model slightly overestimated the total amount of rain that had fallen, simulating 7.2 inches instead of the nearly 6 inches measured by the rain gauge.
In addition to simulating realistic storm environments, the researchers also created simulation models that replaced cities with undeveloped land and lowered temperatures to pre-industrial levels. This helped the researchers determine how cities and climates each influenced the storm, as well as their combined effects.
Although the effects of climate and the city together have the largest impact, lead author Long Yang, an associate professor at Nanjing University, says that, taken separately, the city’s influence is equal or greater. than the effects of climate change.
“We are the first to reveal that regional effects through soil-atmosphere interactions on extreme precipitation are comparable to or more severe than those caused by large-scale processes,” said Yang. caused by climate.
The model applies to an extreme storm. However, Niyogi says the results are consistent with different urban precipitation studies and show the importance of incorporating the effects of urbanization and regional landscapes into general climate models.
He also added that climate change adaptation offers the opportunity to plan for more resilient communities that can help shape desirable climate outcomes, such as cities with can drive storms out of flood prone areas.
“On a more local scale, there are immediate ways to develop climate resilience, where you don’t have to wait for more than 100 countries to sign off on declarations,” says Niyogi. “It’s something you can do at a city scale, at a regional scale.”
The study’s additional co-authors are Professors Guangheng Ni and Fuqiang Tian from Tsinghua University in China.
JOURNEYS
Geophysical research letter
RESEARCH METHODS
Simulation / computational modeling
RESEARCH SUBJECTS
Do not apply
ARTICLE TITLE
Urbanization Exacerbating Precipitation over European Suburbs in Warming Climates
ARTICLE PUBLICATION DATE
October 16, 2021
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