Human activity is intensifying deadly flooding, study shows

Researchers at Columbia Engineering have found that storm runoff extremes and flash flooding have been dramatically increasing in response to both human-induced and natural climate change.

The world’s most recent devastating storms – Hurricane Florence, Hurricane Michael, and Super Typhoon Mangkhut –  demonstrated the widespread damage that can be caused by weather extremes. Flash flooding has caused more deaths and higher economic losses than any other severe weather-related hazard.

Losses from flooding have been steadily rising over the past five decades, and those losses exceeded $30 billion per year in the last ten years. Nearly one billion people now live in floodplains, a fact that highlights the urgency to better understand and anticipate river flooding from extreme weather events.

The findings of the new study show a large increase in both precipitation and runoff extremes driven by both human activity and climate change.

The experts also found that storm runoff has a stronger response to human-induced changes than precipitation, which suggests that storm runoff extremes are going to increase dramatically.  

Study lead author Pierre Gentine is an associate professor of Earth and Environmental Engineering at Columbia.

“Our work helps explain the underlying physical mechanisms related to the intensification of precipitation and runoff extremes,” said Professor Gentine. “This will help improve flood forecasting and early-warning alerts. Our findings can help provide scientific guidance for infrastructure and ecosystem resilience planning, and could help formulate strategies for tackling climate change.”

Study co-author Jiabo Yin is a visiting student from Wuhan University that is working on Professor Gentine’s team.

“We were trying to find the physical mechanisms behind why precipitation and runoff extremes are increasing all over the globe,” said Yin. “We know that precipitation and runoff extremes will significantly intensify in the future, and we need to modify our infrastructures accordingly. Our study establishes a framework for investigating the runoff response.”

The study is published in the journal Nature Communications.

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By Chrissy Sexton, Earth.com Staff Writer

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