Quantcast

Houston’s Tall Buildings and Concrete Sprawl Made Harvey’s Rain and Flooding Worse

Popular
Downtown Houston surrounded by flooding and mist after Hurricane Harvey. Prairie Pictures / The Image Bank / Getty Images

The science is clear that in order to prevent more extreme weather events like hurricanes, we need to stop burning fossil fuels. Thursday, EcoWatch reported on a study that found major hurricanes in the past decade were made five to 10 percent wetter because of global warming, and another study last year calculated that the record rainfall that flooded Texas during Hurricane Harvey was made three times more likely due to climate change.


Now, a second study focusing on Hurricane Harvey that was published in Nature Wednesday pointed to another thing we can do to reduce the impact of these devastating storms: change the way we build cities.

Researchers at the University of Princeton and the University of Iowa used computer models and historical data to determine that urbanization in Houston made both the flooding and the record rainfall worse than it would have been in a rural area, a Princeton press release explained.

While this can help Houston make changes going forward, it also has major implications for other Southeast and Gulf cities facing the threat of wetter storms.

"Hurricane Harvey's impacts on Houston highlight hazards to coastal cities along the Gulf Coast and Eastern Seaboard of the United States," co-author and Princeton civil and environmental engineering professor James Smith said in the press release. "An unfortunate repeat performance from Hurricane Florence this year underscores the problems of extreme tropical cyclone rainfall in urban settings."

Houston has both grown up and out in recent years, and both of those had an impact on rainfall and flood risk. But how does that work exactly?

Flooding

Urbanization's impact on flooding is pretty common sense. More concrete streets and sidewalks means less water can be absorbed into the ground, leaving it to flood those streets instead.

Researchers compared yearly flood peaks with population growth, and also compared the contemporary results with flood peaks from the 1950s, when Houston was much less built up. Sure enough, as development increased, so did flood risk.

"Urbanization is generally associated with a significant reduction in storm-water infiltration," Director of Iowa's Hydroscience and Engineering research center (IIHR) Gabriele Villarini explained in the press release. "Houston has experienced one of the most impressive urban-development booms in U.S. history, and with growth comes an increase in impervious surfaces. This increase in urbanization, combined with the region's flat clay terrain, represents a very problematic mix, even with flood-mitigation measures in place."

Rainfall

The reason that urbanization increases rainfall is a little more complicated. Basically, the increased number and height of buildings creates something called "surface roughness" that increases friction and, therefore, rainfall when the storm winds blow over it.

"When Hurricane Harvey blew into Houston, it literally got snagged on the city's tall skyscrapers and towers," Villarini said. "The friction caused by high winds buffeting tall buildings created a drag effect that influenced air and heat movement and resulted in optimal conditions for precipitation."

Researchers used computer models to run the same storm over the same geographic area with Houston's current infrastructure and with open fields. They found that less rain fell and that rainfall patterns changed in the imaginary rural Houston, as this graphic shows.

Rainfall from Harvey in urban v. rural Houston@3rdrockhome

Now that the researchers have shown the impact current urban design has on storms, they hope that urban planners will use that information to reduce risk.

"For every new roadway poured and for every new high-rise erected, there is an increased risk for more adverse rainfall and flooding, and that's certainly something that city officials and residents should consider when they contemplate future growth," Villarini concluded.

EcoWatch Daily Newsletter

A glacier is seen in the Kenai Mountains on Sept. 6, near Primrose, Alaska. Scientists from the U.S. Geological Survey have been studying the glaciers in the area since 1966 and their studies show that the warming climate has resulted in sustained glacial mass loss as melting outpaced the accumulation of new snow and ice. Joe Raedle / Getty Images

By Mark Mancini

On Aug. 18, Iceland held a funeral for the first glacier lost to climate change. The deceased party was Okjökull, a historic body of ice that covered 14.6 square miles (38 square kilometers) in the Icelandic Highlands at the turn of the 20th century. But its glory days are long gone. In 2014, having dwindled to less than 1/15 its former size, Okjökull lost its status as an official glacier.

Read More Show Less
Members of Chicago Democratic Socialists of America table at the Logan Square Farmers Market on Aug. 18. Alex Schwartz

By Alex Schwartz

Among the many vendors at the Logan Square Farmers Market on Aug. 18 sat three young people peddling neither organic vegetables, gourmet cheese nor handmade crafts. Instead, they offered liberation from capitalism.

Read More Show Less
Sponsored
StephanieFrey / iStock / Getty Images

By Lauren Panoff, MPH, RD

Muffins are a popular, sweet treat.

Read More Show Less
Hackney primary school students went to the Town Hall on May 24 in London after school to protest about the climate emergency. Jenny Matthews / In Pictures / Getty Images

By Caroline Hickman

Eco-anxiety is likely to affect more and more people as the climate destabilizes. Already, studies have found that 45 percent of children suffer lasting depression after surviving extreme weather and natural disasters. Some of that emotional turmoil must stem from confusion — why aren't adults doing more to stop climate change?

Read More Show Less
Myrtle warbler. Gillfoto / Flickr / CC BY-SA 2.0

Bird watching in the U.S. may be a lot harder than it once was, since bird populations are dropping off in droves, according to a new study.

Read More Show Less
Sponsored
Amazon CEO Jeff Bezos announces the co-founding of The Climate Pledge at the National Press Club on Sept. 19 in Washington, DC. Paul Morigi / Getty Images for Amazon

The day before over 1,500 Amazon.com employees planned a walkout to participate in today's global climate strike, CEO Jeff Bezos unveiled a sweeping plan for the retail and media giant to be carbon neutral by 2040, 10 years ahead of the Paris agreement schedule.

Read More Show Less

By Winona LaDuke

For the past seven years, the Anishinaabe people have been facing the largest tar sands pipeline project in North America. We still are. In these dying moments of the fossil fuel industry, Water Protectors stand, prepared for yet another battle for the water, wild rice and future of all. We face Enbridge, the largest pipeline company in North America, and the third largest corporation in Canada. We face it unafraid and eyes wide open, for indeed we see the future.

Read More Show Less
The climate crisis often intensifies systems of oppression. Rieko Honma / Stone / Getty Images Plus

By Mara Dolan

We see the effects of the climate crisis all around us in hurricanes, droughts, wildfires, and rising sea levels, but our proximity to these things, and how deeply our lives are changed by them, are not the same for everyone. Frontline groups have been leading the fight for environmental and climate justice for centuries and understand the critical connections between the climate crisis and racial justice, economic justice, migrant justice, and gender justice. Our personal experiences with climate change are shaped by our experiences with race, gender, and class, as the climate crisis often intensifies these systems of oppression.

Read More Show Less