In July 2010, monsoon rains put one fifth of Pakistan under water. In December 2010 and January 2011, Tropical Cyclone Tasha and a wet year combined to drown Queensland, Australia. And in the United States this May, flooding on the Mississippi River has displaced thousands of people. Over months or a few short hours, extreme rain can interact with the right combination of topography, land use and climate to trigger deadly and costly floods. Submerged houses in Louisiana due to extreme flooding caused by Hurricane Katrina To better understand and predict floods scientists have developed...