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USGS Work Is Leading to New Operations for Glen Canyon Dam
USGS scientists from the Coastal and Marine Geology Program (CMGP) have been contributing to the assessment of sand resources in Grand Canyon for more than a decade, through sedimentologic studies (Dave Rubin, Menlo Park, CA) and the use of sidescan sonar (Roberto Anima, Menlo Park, CA), underwater video (Hank Chezar, Menlo Park, CA), and other marine-research technologies. Their findings contributed to a decision by DOI to release an unusually large volume of water from Glen Canyon Dam in spring 1996 to determine, in part, whether this artificial "flood" could move sand from the river's main channel into sand bars along its banks. CMGP contributions to sand-bar restoration efforts in Grand Canyon are continuing to affect DOI management decisions. In August 2000, Dave Rubin and colleagues from the USGS (David Topping), Utah State University (Jack Schmidt), and Northern Arizona University (Joe Hazel and Matt Kaplinski) were requested to summarize their recent published findings for the office of the Secretary. To respond to this request, the group worked with their program manager at the USGS Grand Canyon Monitoring and Research Center (Ted Melis) and prepared a memo reporting that restoration efforts—including the 1996 Grand Canyon flood experiment—were failing to meet the sediment goals established by the Glen Canyon Adaptive Management Program. The memo explained why the restoration efforts were failing and how operations in Glen Canyon Dam might be altered to optimize sand-bar restoration. The memo written by Rubin and his colleagues summarized five technical articles that had been published in the journals Water Resources Research and Geology and in a special volume on the 1996 flood experiment published by the American Geophysical Union. In addition to the normal scientific review of these five articles, the memo itself was carefully reviewed by the Technical Work Group and its sediment subcommittee of the Adaptive Management Work Group (groups established as part of the Glen Canyon Adaptive Management Program). These groups endorsed the findings in the memo, and the Grand Canyon Monitoring and Research Center (also part of the Glen Canyon Adaptive Management Program) made a formal proposal to adopt the recommendations. In April, a vote was conducted by the full Adaptive Management Work Group, and the proposed flow recommendations were approved by a vote of 17 to 1 (with 1 abstention). These recommended changes to dam operations have been forwarded to Secretary of the Interior Gale Norton. The media have reported these recent events (see Related Web Sites below) in USA Today (April 11), The Arizona Republic (April 26), the Arizona Daily Sun (April 26), and the New York Times (April 26 and June 11). The scientific findings summarized in the memo evolved into an article for Eos (in press, expected to be published in June 2002). New technology and a better understanding of sediment transport gained from the Grand Canyon work are now being incorporated into marine sediment-transport studies.
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in this issue:
Glen Canyon Dam
Gulf of Maine GIS Workshop for Teachers Florida Caribbean Science Center Open House Communicating Science in a Virtual World Continental-Shelf Territory Rights New Woods Hole Chief Scientist University of Minnesota Visitor
Timely Publication for Gulf of Mexico Mercury Concerns |
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U. S. Department of the Interior | U.S. Geological Survey
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