NASA scientists, a University of Iowa scientist, and representatives from the Iowa Flood Center met Tuesday on a Google+ Hangout open to the public. They discussed NASA’s international Global Precipitation Measurement mission, a system of satellites that will measure rainfall data from space and try to predict when and where floods will strike.

Iowa Flood Center director and University of Iowa civil and environmental engineering Professor Witold Krajewski said the flood of 2008 came on very suddenly, and in all, countless city blocks were inundated by the Cedar River’s reach.

“It was a case of a traffic jam in the river network,” he said. “There was already a flood wave moving downstream, and that coincided with a response to a torrential flash-flood event. And the two collided in downtown Cedar Rapids.”

While overseeing a system of rain gauges from a temporary trailer in Iowa Tuesday, NASA scientist Walt Peterson said the fundamental measurement in predicting the threat of floods is the rainfall rate.

He said the federal agency settled on Iowa because of repeated widespread flood concerns over the past few years. 

Peterson said the rain gauge data will be used to calibrate the sensors in outer space to more accurately measure from a global scale.