Author(s): F. M. Henderson; R. Gerard

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Keywords: No Keywords

Abstract: The paper presents the results of a preliminary theoretical study of the sudden changes in depth and velocity that can be caused by the sudden formation, failure and re-formation of ice jams. The problem is essentially that of the classic dam break. It is shown that the surge formed downstream by the sudden failure of an ice jam cannot have a height greater than one-half of the difference in water level across the original jam, but that subsequent re-formation of the jam may produce water levels behind the new jam which exceed the surge level by up to six times the height of the surge. It is also shown that the reflection of negative waves from the backwater curve behind the original jam can produce a surge attenuation effect which is quite large and, unlike normal flood wave subsidence increases in direct proportion to the slope of the river channel bed. The paper concludes with a discussion of some recent field observations, and of the direction that should be taken by further work on the subject.

DOI:

Year: 1981