A Comprehensive Database of Flood Events in the Contiguous United States from 2002 to 2013

Abstract

otwithstanding the rich record of hydrometric observations compiled by the U.S. Geological Survey (USGS) across the contiguous United States (CONUS), flood event catalogues are sparse and incomplete. Available databases or inventories are mostly survey- or report-based, impact-oriented, or limited to flash floods. These data do not represent the full range of flood events occurring in CONUS in terms of geographical locations, severity, triggering weather, or basin morphometry. This study describes a comprehensive dataset consisting of more than half a million flood events extracted from 6,301 USGS flow records and radar-rainfall fields from 2002 to 2013, using the characteristic point method. The database features event duration; first- (mass center) and second- (spreading) order moments of both precipitation and flow; flow peak and percentile; event runoff coefficient; base flow; and information on the basin geomorphology. It can support flood modeling, geomorphological and geophysical impact studies, and instantaneous unit hydrograph and risk analyses, among other investigations. Preliminary data analysis conducted in this study shows that the spatial pattern of flood events affected by snowmelt correlates well with the mean annual snowfall accumulation pattern across CONUS; the basin morphometry affects the number of flood events and peak flows; and the concentration time and spreadness of the flood events can be related to the precipitation first- and second-order moments.