Ancient Floods, Modern Hazards: Principles and Applications of Paleoflood Hydrology: (Edited by P. K. House, R. H. Webb, V. R. Baker, and D. R. Levish)

Abstract

Paleoflood hydrology, as it developed in the 1970s, identified slackwater flood deposits (SWD) as the primary indicator of a historically high stage of a river, i.e., a “paleostage indicator.” Such SWDs are believed to have formed in eddies at the mouths of tributaries of rivers that caused sedimentation of sands and silts in topographically elevated locales relative to the present position of such rivers. If undisturbed by even larger floods, there is a reasonable likelihood that pedogenic processes will create a soil horizon within the SWD that can be age-dated using 14C. Thus an approximate age of the paleoflood can be estimated as well as the paleostage, i.e., the maximum flood stage. Using one-dimensional hydraulic models of bedrock channels and estimates of bed roughness described by Manning's coefficient, the paleoflood hydrologist employs the same tools as used by engineering hydrologists to estimate peak flood discharges, e.g., the step-backwater method. Consequently, geomorphologists and paleoflood hydrologists have been able to contribute their insight to flood-frequency analysis, previously the sole domain of engineering hydrologists. Some years have past since Environmental & Engineering Geoscience published a research paper on low-probability floods and their estimation (Malamud et al., 1996). Paleoflood hydrology is, however, a vibrant area of scientific research that has particular significance to dam safety and floodplain protection of critical structures, such as nuclear reactors, and to engineering geology and fluvial geomorphology in general. This monograph, by the principal actors in paleoflood hydrology, is rich in detail, definitive in scope, and of moderate cost ($75 hardback). Ancient …