Physical Sciences and Mathematics Commons^™

Application And National Geographic Information System Database To Support Two-Year Flood And Threshold Runoff Estimates, Seann Reed, Dennis Johnson, Timothy Sweeney

United States Department of Commerce: Staff Publications

A computer application and national geospatial database have been developed to support the calculation of flooding flow (Q_f) and threshold runoff across the conterminous United States and Alaska. Flooding flow is the flow required to cause a stream to slightly overflow its bank and cause damage. Threshold runoff [L], defined as the depth of runoff required to cause flooding, is computed as flooding flow divided by the unit hydrograph peak flow. A key assumption in this work is that the two-year return flood (Q₂) is a useful surrogate for flooding flow. The application described here computes …