Author(s): Henry S. Santeford; George R. Alger
Linked Author(s):
Keywords: No Keywords
Abstract: In 1982 the authors began a study of the effects of a floating ice cover on river stage. The initial studies centered on river reaches with uniform and/or accelerating flow (i. e. uniform or drawdown profiles). Subsequently, the field studies were expanded to include river reaches with decelerating flow (i. e. backwater profiles). The results of these early field studies showed that the effects of a floating ice cover on river stage depended on the hydraulics of the river reach. For uniform and/or accelerating flow, a floating cover caused an increase in stage equal to the buoyant di spl acement of the cover. For the decelerating flow, the floating cover produced no change whatsoever in the stage. A series of laboratory experiments have been performed in a small flume in hopes of further defining the behavior of backwater profiles and their response to the introduction of a floating cover. The laboratory studies suggest that the backwater profile may display one of two possible configurations depending upon the "degree of backwater, " i. e. the increase in downstream depth above normal depth relative to the change in elevation of the bottom from one end of the reach to the other. Neither configuration resembles what is predicted by open channel textbooks, and neither can be approximated through use of the conventional step method of computation. The introduction of a floating cover on either configuration had no effect on stage and is the same response as experienced in the field studies.
Year: 1992