The response of source-bordering aeolian dunefields to sediment-supply changes 2: Controlled floods of the Colorado River in Grand Canyon, Arizona, USA

Aeolian Research
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Abstract

In the Colorado River downstream of Glen Canyon Dam in the Grand Canyon, USA, controlled floods are used to resupply sediment to, and rebuild, river sandbars that have eroded severely over the past five decades owing to dam-induced changes in river flow and sediment supply. In this study, we examine whether controlled floods, can in turn resupply aeolian sediment to some of the large source-bordering aeolian dunefields (SBDs) along the margins of the river. Using a legacy of high-resolution lidar remote-sensing and meteorological data, we characterize the response of four SBDs (a subset of 117 SBDs and other aeolian-sand-dominated areas in the canyon) during four sediment-laden controlled floods of the Colorado River in 2012, 2013, 2014, and 2016. We find that aeolian sediment resupply unambiguously occurred in 8 of the 16 instances of controlled flooding adjacent to SBDs. Resupply attributed to individual floods varied substantially among sites, and occurred with four, three, one, and zero floods at the four sites, respectively. We infer that the relative success of controlled floods as a regulated-river management tool for resupplying sediment to SBDs is analogous to the frequency of resupply observed for fluvial sandbars in this setting, in that sediment resupply was estimated to have occurred for roughly half of the instances of recent controlled flooding at sandbars monitored separately from this study. We find the methods developed in this, and a companion study, are effective tools to quantify geomorphic changes in sediment storage, along linked fluvial and aeolian pathways of sedimentary systems.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The response of source-bordering aeolian dunefields to sediment-supply changes 2: Controlled floods of the Colorado River in Grand Canyon, Arizona, USA
Series title Aeolian Research
DOI 10.1016/j.aeolia.2018.02.004
Volume 32
Year Published 2018
Language English
Publisher Elsevier
Contributing office(s) Southwest Biological Science Center
Description 16 p.
First page 154
Last page 169
Country United States
State Arizona
Other Geospatial Colorado River, Grand Canyon