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Sources of uncertainty in flood inundation maps

January 1, 2009

Flood inundation maps typically have been used to depict inundated areas for floods having specific exceedance levels. The uncertainty associated with the inundation boundaries is seldom quantified, in part, because all of the sources of uncertainty are not recognized and because data available to quantify uncertainty seldom are available. Sources of uncertainty discussed in this paper include hydrologic data used for hydraulic model development and validation, topographic data, and the hydraulic model. The assumption of steady flow, which typically is made to produce inundation maps, has less of an effect on predicted inundation at lower flows than for higher flows because more time typically is required to inundate areas at high flows than at low flows. Difficulties with establishing reasonable cross sections that do not intersect and that represent water-surface slopes in tributaries contribute additional uncertainties in the hydraulic modelling. As a result, uncertainty in the flood inundation polygons simulated with a one-dimensional model increases with distance from the main channel.

Citation Information

Publication Year 2009
Title Sources of uncertainty in flood inundation maps
DOI 10.1111/j.1753-318X.2009.01029.x
Authors J. D. Bales, C.R. Wagner
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Flood Risk Management
Index ID 70034690
Record Source USGS Publications Warehouse