Sand-storage changes in the Colorado River downstream from the Paria and Little Colorado rivers, April 1994 to August 1995

Graf, Julia B.; Marlow, Jonathan E.; Rigas, P.D.; Jansen, Samuel M.D.

doi:10.3133/ofr97206

Cited by 4 publications

(2 citation statements)

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“…[31] Channel-margin deposits were not directly surveyed before or after the 1996 Controlled Flood, and sedimentthickness changes were based on observations of excavated trenches (D. Rubin, USGS, and J. C. Schmidt, Utah State University, unpublished data, 1999). During the September 2000 Powerplant Capacity Flow, channel-margin deposits were surveyed at 6 cross-sections previously established by Graf et al [1995] [32] Results from the five GIS reaches were used to determine the aerial proportion of eddy, channel-margin deposit, and main-channel storage in Marble Canyon (Table 1). We multiplied these areas by the average change in deposit thickness in order to estimate the total volume change in each storage environment.…”

Section: Topographic Datamentioning

confidence: 99%

Influence of a dam on fine‐sediment storage in a canyon river

et al. 2006

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[1] Glen Canyon Dam has caused a fundamental change in the distribution of fine sediment storage in the 99-km reach of the Colorado River in Marble Canyon, Grand Canyon National Park, Arizona. The two major storage sites for fine sediment (i.e., sand and finer material) in this canyon river are lateral recirculation eddies and the mainchannel bed. We use a combination of methods, including direct measurement of sediment storage change, measurements of sediment flux, and comparison of the grain size of sediment found in different storage sites relative to the supply and that in transport, in order to evaluate the change in both the volume and location of sediment storage. The analysis shows that the bed of the main channel was an important storage environment for fine sediment in the predam era. In years of large seasonal accumulation, approximately 50% of the fine sediment supplied to the reach from upstream sources was stored on the main-channel bed. In contrast, sediment budgets constructed for two short-duration, high experimental releases from Glen Canyon Dam indicate that approximately 90% of the sediment discharge from the reach during each release was derived from eddy storage, rather than from sandy deposits on the main-channel bed. These results indicate that the majority of the fine sediment in Marble Canyon is now stored in eddies, even though they occupy a small percentage ($17%) of the total river area. Because of a 95% reduction in the supply of fine sediment to Marble Canyon, future high releases without significant input of tributary sediment will potentially erode sediment from long-term eddy storage, resulting in continued degradation in Marble Canyon.

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Section: Topographic Datamentioning

confidence: 99%

Influence of a dam on fine‐sediment storage in a canyon river

et al. 2006

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“…The survey used established monuments (Graf et al, 1994;Fig. 2) as navigation control of the geophysical traverses.…”

Section: Methods Navigationmentioning

confidence: 99%

Comparison of sand distribution between April 1994 and June 1996 along six reaches of the Colorado River in Grand Canyon, Arizona

Anima¹,

Marlow²,

Rubin³

et al. 1998

Open-File Report

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Two geophysical surveys in April, 1994 and June, 1996 collected data along 15 reaches of the Colorado River in Grand Canyon. This report discusses six of those reaches between the Little Colorado River and Tanner Rapid. The surveys imaged the distribution of sand and mixtures of sand with pebbles, cobbles and boulders stored within the reaches. The surveys established a baseline of sand distribution before an experimental flood in March, 1996 and mapped changes in the areal distribution of sand within each reach after the 1996 flood. This study does not attempt to estimate the volume change in sediment stored within the reaches. Survey control relied on a network of monuments established by the Glen Canyon Environmental Study (GCES) and the United States Geological Survey Water Resources Division (WRD). The 1994 survey utilized a high-resolution seismic-reflection profiler, a side-scan sonar system, a bathymetric profiler, and underwater video system. The 1996 survey did not use the high-resolution seismic profiler because the system was generally unsuccessful in detecting subsurface structure due to multiples created in shallow water. Both surveys used underwater video to collect images of the river bed to validate our interpretations of the side-scan record. This report describes data collection, interpretation, and discusses trends found along the reaches studied in detail.

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