FloodsHouston's urban sprawl dramatically increased rainfall, flooding damage during Hurricane Harvey
Houston’s urban landscape directly contributed to the torrential rainfall and deadly flooding experienced during Hurricane Harvey in August 2017, according to Princeton and University of Iowa researchers. The researchers report that Houston’s risk for extreme flooding during the hurricane — a category 4 storm that caused an estimated $125 billion in damage and killed 68 people — was 21 times greater due to urbanization.
Houston’s urban landscape directly contributed to the torrential rainfall and deadly flooding experienced during Hurricane Harvey in August 2017, according to Princeton and University of Iowa researchers. The researchers report in the journal Nature 15 November that Houston’s risk for extreme flooding during the hurricane — a category 4 storm that caused an estimated $125 billion in damage and killed 68 people — was 21 times greater due to urbanization.
Using computer models and weather data, the researchers recreated Hurricane Harvey and compared the total rainfall with urban buildup to total rainfall without urban buildup. The results indicated that human-made development helped create a wetter hurricane — one that dropped 40 to 60 inches of rain over four days — as well as more serious flooding, with higher flood peaks and greater overall damage.
The results highlight the human role in extreme weather events, as well as the need to consider urban and suburban development when calculating hurricane risk and preparing for hurricane damage and recovery, the authors said. The study also accentuates the need to understand the compounded human impact on rainfall and flooding caused by urbanization and climate change.
“Our focus on the role of urbanization was aimed at providing a fuller perspective of human activities on Harvey’s rainfall and flooding,” said co-author Gabriel Vecchi, a Princeton professor of geosciences and the Princeton Environmental Institute (PEI). “Humans have influenced both climate, through greenhouse gas emissions, and the local environment around Houston through urbanization in ways that we thought could have affected rainfall and flooding from Harvey.”
Princeton says that the researchers found that as Houston’s urban center grew upward and outward, flood risk changed, including a greater risk of higher flood peaks and more serious and dangerous flooding overall. As the city’s miles of impervious sidewalks and streets increased, heavy rainfall could not be absorbed into the ground.
