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Grand Canyon riverbed sediment changes, experimental release of September 2000 - a sample data set

October 1, 2003

An experimental water release from the Glen Canyon Dam into the Colorado River above Grand Canyon was conducted in September 2000 by the U.S. Bureau of Reclamation. The U.S. Geological Survey (USGS) conducted sidescan sonar surveys between Glen Canyon Dam (mile -15) and Diamond Creek (mile 220), Arizona (mile designations after Stevens, 1998) to determine the sediment characteristics of the Colorado River bed before and after the release. The first survey (R3-00-GC, 28 Aug to 5 Sep 2000) was conducted before the release when the river was at its Low Summer Steady Flow (LSSF) of 8,000 cfs. The second survey (R4-00-GC, 10 to 18 Sep 2000) was conducted immediately after the September 2000 experimental release when the average daily flow was as high as 30,800 cfs as measured below Glen Canyon Dam (Figure 2). Riverbed sediment properties interpreted from the sidescan sonar images include sediment type and sandwaves; overall changes in these properties between the two surveys were calculated.

Sidescan sonar data from the USGS surveys were processed for segments of the Colorado River from Glen Canyon Dam (mile -15) to Phantom Ranch (mile 87.7, Figure 3). The surveys targeted pools between rapids that are part of the Grand Canyon Monitoring and Research Center (GCMRC physical sciences study.

Maps interpreted from the sidescan sonar images show the distribution of sediment types (bedrock, boulders, pebbles or cobbles, and sand) and the extent of sandwaves for each of the pre- and post-flow surveys. The changes between the two surveys were calculated with spatial arithmetric and had properties of fining, coarsening, erosion, deposition, and the appearance or disappearance of sandwaves.

Publication Year 2003
Title Grand Canyon riverbed sediment changes, experimental release of September 2000 - a sample data set
DOI 10.3133/ofr03265
Authors Florence L. Wong, Roberto J. Anima, Peter Galanis, Jennifer Codianne, Yu Xia, Randy Bucciarelli, Michael Hamer
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 2003-265
Index ID ofr03265
Record Source USGS Publications Warehouse
USGS Organization Pacific Coastal and Marine Science Center