Catastrophic floods: scientific understanding and continuing human ignorance
by
Victor R. Baker
Department of Hydrology and Water Resources, The University of Arizona

Flooding is arguably the most pervasive and continually destructive of natural hazards. Flood damage results from human occupancy of rather easily identified flood-prone areas. Despite the dominating social dimension to this hazard, much flood hazard research is misguided to study of relatively frequent flood phenomena and to a focus on theoretical issues of little relevance to the realities of the hazard. Particularly unproductive is work on the pseudoscientific notion of the "hundred-year flood" that is commonly used in US regulatory practice. In addition to being an oxymoron (having to do neither with a hundred real years, nor with real floods), the "hundred-year flood" paradigm misrepresents the understanding of large rare floods as a matter of extrapolation from measurements of small, common floods. However, it is a commonsensical truism that a scientific understanding of large, rare floods must involve the scientific study of large, rare floods. Nevertheless, this truism is denied in much of current flood science by the presumption that such floods are inaccessible to study. While the floods themselves are indeed rare, their effects are not. The science of paleoflood hydrology seeks to understand large, rare floods by studying their past effects. The more intense the flooding, the more prolonged and easily discerned the past evidence to that flooding. While some of these past flood phenomena are relevant to the continuing flood hazards posed to people, other evidence applies to superfloods, so large that they are of only very remote hazard possibility. However, the impact of such superfloods have been so immense that they have likely provided the sources of flood myths that are found in the oral traditions of nearly all human cultures. Particularly immense superfloods occurred in North America and Asia towards the end of the last ice age. These floods produced short-term discharges of water comparable in magnitude to some of Earth's ocean currents.

Date received: April 26, 2002

Copyright © 2002 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caji-13.