All living things need water to survive. But when there's too much rain, a flood can happen. Learn how floods form and how we try to avoid them.

"Discover the extraordinary power of nature in this comprehensive visual encyclopedia. Full of fascinating facts and dramatic photography and based on the latest research, this is the definitive guide to natural disasters. You'll discover their causes, explore how they unfold, and see for yourself the ways in which scientists and rescue workers protect the public." -- Back cover. "This comprehensive visual encyclopedia is the perfect introduction...