Ice jam characteristics, Liard–Mackenzie rivers confluence

Publisher Website
Google Scholar
Abstract
Breakup of the Liard and Mackenzie rivers near Fort Simpson, N.W.T., was monitored from 1978 to 1984. In each year, ice jams ranging in length from 10 to 22 km formed at the Liard River mouth. Although the thickness of some of the jams exceeded 5 m, the volume of ice within the accumulations represented less than 20% of the ice contained within the pre-breakup ice cover of the Liard River main stem. The composition and thickness of the ice jams was related to whether breakup was a 'thermal' or 'mechanical' event. The majority were mechanical breakups and produced much thicker jams and higher water levels than did thermal breakups.Stage–discharge rating curves were developed for the site using two appoaches based on the equilibrium jam theory. The first employed jam parameters calculated for the 1983 jam and the second used a simplified approach suggested by S. Beltaos. Both approaches predicted stage increases of approximately 4–8 m above that which would result from similar discharge under open water conditions. Furthermore, the first approach resulted in a coefficient of internal friction of 1.06, supporting the suggestion that this parameter may have a mean value of 1.2. Key words: floating ice, floods, ice jams, ice breakup.

This publication has 0 references indexed in Scilit: