Why was flooding during Harvey so bad?
One spot in Nederland recorded over 60 inches of rainfall. That is a record for the United States.
HOUSTON — Why was flooding during Harvey so bad? A lot of rain fell in the Houston area during Hurricane Harvey. One spot in Nederland recorded over 60 inches of rainfall. That is a record for the United States.
A study in the journal Nature looked at why.
Study finds Houston buildings increased rainfall
It looked at data from the city of Houston during Harvey and compared it to how much rain would have fallen if the city and suburbs were never built. The study found that just by existing the city and its buildings increased rainfall.
Hot, moist wind hits buildings
That’s because a tropical system is made up of hot, moist wind. It blows in from the Gulf of Mexico and when it hits the buildings in the big city that air is forced up.
When it goes up, it hits colder air condensing into droplets that end up falling as rain. So the more buildings you have the more air goes up and the more rain comes down.
Study finds pavement prevented rain from being soaked into the ground
The study didn’t just look up it also looked down, at all the sprawling development and pavement that makes up Houston. Those features mean that the rain has nowhere to go.
Pavement impervious to water
Paved areas are impervious to water, so that record amount of rain couldn’t be soaked into the ground quickly spreading floodwaters throughout the nation’s fourth largest city.