Browse wiki

From CSDMS
Flood hazards can increase or decrease as Flood hazards can increase or decrease as a result of changes in the frequency of high flows and changes in the geometry of river channels, through aggradation, incision, or widening. Across the US, Slater et al. (2015) found that a statistically significant majority of studied sites saw increases in the frequency of flooding over the past several decades. Notably, the magnitude of channel response and hydrologic non-stationarity varied between channels within a region. Here, we focus in on a single region, the Pacific Northwest, and ask 1) can the geomorphic characteristics of a basin explain historical changes in flood hazard? And, 2) how will flood risk change with climate change in relation to source-to-sink sediment dynamics? As a first step in understanding the sensitivity of different basins to future climate change, we look at historical records of both channel geometry change and discharge records at ~60 USGS gage sites across Washington state. We find substantial variation among the studied sites in the magnitude of channel change (quantified in terms of changes in the stage-discharge relationship) over the past 3 decades. Some channels have maintained a steady stage-discharge relationship over 30 years, while others change dramatically on an annual basis. Many, but not all, of these unstable channels drain basins with retreating alpine glaciers. Inspecting the discharge records, we find substantial variation as well, likely driven by the differences in hydrologic regime. In the future, we will use this understanding of historical channel sensitivity to inform our predictive models of both channel geometry change and non-stationarity in high flows.change and non-stationarity in high flows.  +
How do source-to-sink geomorphic processes mediate flood hazards? Using historical changes to inform predictions  +
Seattle  +
erkani@uw.edu  +  and swanderson@usgs.gov  +
University of Washington, CEE  +  and USGS  +
Istanbulluoglu  +  and Anderson  +
Seattle  +  and Tacoma  +
University of Washington  +
206-679-0339  +
Washington  +
United States  +
Creation date"Creation date" is a predefined property that corresponds to the date of the first revision of a subject and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
22:23:32, 6 March 2018  +
Has query"Has query" is a predefined property that represents meta information (in form of a <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Subobject">subobject</a>) about individual queries and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
Last editor is"Last editor is" is a predefined property that contains the page name of the user who created the last revision and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
21:26:27, 8 May 2018  +
Washington  +