HR: 16:30h
AN: H24E-03    [Abstracts]
TI: Paleoflood Data, Extreme Floods and Frequency: Data and Models for Dam Safety Risk Scenarios
AU: * England, J F
EM: jengland@do.usbr.gov
AF: Bureau of Reclamation, 86-68530, Bldg. 67, Denver Federal Center, Denver, CO 80225, United States
AU: Godaire, J
EM: jgodaire@do.usbr.gov
AF: Bureau of Reclamation, 86-68530, Bldg. 67, Denver Federal Center, Denver, CO 80225, United States
AU: Klinger, R
EM: rklinger@do.usbr.gov
AF: Bureau of Reclamation, 86-68530, Bldg. 67, Denver Federal Center, Denver, CO 80225, United States
AB: Extreme floods and probability estimates are crucial components in dam safety risk analysis and scenarios for water-resources decision making. The field-based collection of paleoflood data provides needed information on the magnitude and probability of extreme floods at locations of interest in a watershed or region. The stratigraphic record present along streams in the form of terrace and floodplain deposits represent direct indicators of the magnitude of large floods on a river, and may provide 10 to 100 times longer records than conventional stream gaging records of large floods. Paleoflood data is combined with gage and historical streamflow estimates to gain insights to flood frequency scaling, model extrapolations and uncertainty, and provide input scenarios to risk analysis event trees. We illustrate current data collection and flood frequency modeling approaches via case studies in the western United States, including the American River in California and the Arkansas River in Colorado. These studies demonstrate the integration of applied field geology, hydraulics, and surface-water hydrology. Results from these studies illustrate the gains in information content on extreme floods, provide data- based means to separate flood generation processes, guide flood frequency model extrapolations, and reduce uncertainties. These data and scenarios strongly influence water resources management decisions.
DE: 1817 Extreme events
DE: 1821 Floods
DE: 1880 Water management (6334)
SC: Hydrology [H]
MN: 2007 Fall Meeting