HR: 16:15h
AN: B12F-02 INVITED     [PDF]
TI: Paleoflood records from anatomical tree-ring signatures
AU: * St. George, S
EM: sstgeorg@nrcan.gc.ca
AF: Geological Survey of Canada, 601 Booth Street, Ottawa, ON K1A 0E8 Canada
AU: Nielsen, E
EM: erik.nielsen@mail.com
AF: Manitoba Geological Survey, 360-1395 Ellice Avenue, Winnipeg, MB R3G 3P2 Canada
AB: Records derived from trees growing in temperate regions have provided annually resolved paleohydrological data that span the last several hundred or thousand years. Unfortunately, conventional tree-ring parameters are often insensitive to shorter-term hydrological fluctuations, such as floods, that occur too quickly to be recorded in ringwidth or isotopic series. Paleoflood reconstructions derived from tree rings have been more successful developing flood records using anatomical signatures (flood rings) caused by defoliation or inundation. Although paleoflood records developed from tree rings are much shorter than those developed from geological evidence, their brevity is offset by their exceptional utility for dating floods to a specific year. Like other flood proxies, flood-ring records can shed light on the past frequency of extreme floods, thereby providing a long-term context for contemporary observations. In some situations, flood-ring records enable one to infer the magnitude of paleofloods based on analogy with more recent floods for which stage and discharge measurements are available. The annual resolution of tree rings also allows flood-ring records to provide credible evidence for synchronized flooding in separate drainage basins, and to tightly constrain linkages between extreme floods and potential forcing mechanisms. With complementary records from tributary rivers and streams, it is possible to obtain additional details concerning the relative contributions of individual sub-basins to past extreme floods. Ultimately, extended flood records derived from tree-ring data may be used to test assumptions of stationarity in annual flood series data, and to develop more accurate estimates of the probability of extreme flooding.
DE: 1821 Floods
DE: 3344 Paleoclimatology
SC: Biogeosciences [B]
MN: 2003 Fall Meeting