"this natural disaster wasn't really all that natural"

Enshayan, director of an environmental center at the University of Northern Iowa, suspects that this natural disaster wasn't really all that natural. He points out that the heavy rains fell on a landscape radically reengineered by humans. Plowed fields have replaced tallgrass prairies. Fields have been meticulously drained with underground pipes. Streams and creeks have been straightened. Most of the wetlands are gone. Flood plains have been filled and developed.

"We've done numerous things to the landscape that took away these water-absorbing functions," he said. "Agriculture must respect the limits of nature." http://www.washingtonpost.com