How geography, climate and policy failures collided

"There's no such thing as a natural disaster," geographers like to say — a reminder that human choices turn hazards into tragedies.

- Agence France-Presse

The Texas flash floods this weekend that left more than a hundred dead, including many children, offer a stark illustration. Here is a look at the intertwined forces that amplified this storm’s impact.

'Flash Flood Alley'

Texas's Hill Country sits in an area known as “Flash Flood Alley’, explains Hatim Sharif, a hydrologist at the University of Texas at San Antonio.

Warm Gulf air rushes up the Balcones Escarpment — a line of steep hills and cliffs that arcs southwest down from near Dallas —cools, and dumps torrents onto thin soils that quickly give way to bedrock.