Documents the research on the effect Glen Canyon Dam has had on the riverine environment of the Colorado River downstream that led to the widely publicized experimental release of water in 1996. Also presents technical reports on the impact of the flooding on the hydrological, sediment transport, aquatic biology, and terrestrial ecology of the Grand Canyon and explores the scientific and economic implications for regulated rivers elsewhere in the world. Three large maps, folded into an envelope, illustrate the effects graphically. The collection of 25 papers is not indexed. Annotation c. Book News, Inc., Portland, OR (booknews.com)
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Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 110.The natural flow of almost every river in the United States has been modified to meet various socioeconomic goals—navigation, irrigation, power generation and flood control. The success of the dams and reservoirs built to achieve these goals has been accompanied by changes in the status of riverine resources downstream, a cause of growing environmental and ecological concern. For example, before Glen Canyon Dam was completed, the Colorado River transported large quantities of sediment in floods as large as 8500 m3/s. After the dam was closed in 1963, dam releases typically were less than the powerplant capacity of 890 m3/s and exhibited large daily flow fluctuations. The river carried little sediment. The daily fluctuations in flow eroded sand bars, and the smaller, controlled flow did not redeposit them. The clear, cold water resulted in increased aquatic productivity such that rainbow trout and other nonnative fishes thrived while most native species were lost or endangered.
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