Analysis of River Ice Motion Near a Breaking Front

• Main Authors: Ferrick, Michael G., Weyrick, Patricia B., Hunnewell, Susan T.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1991
• Subjects: Hydrology; Limnology and Potamology; Snow; Ice and Permafrost; *VELOCITY; POSITION(LOCATION); DYNAMICS; ACCELERATION; THEORY; MOTION; EQUILIBRIUM(GENERAL); TIME; SURFACES; ICE; CONVERGENCE; COVERINGS; BEHAVIOR; RIVERS; CONTINUITY; HYDRAULICS; RADIUS(MEASURE); ICE BREAKUP; MEASUREMENT; *ICE BREAKUP; *ICE; *RIVER ICE; PE62730A; AST42; WU001; BANKS(WATERWAYS); EQUATIONS OF MOTION; BREAKING POINT; ICE COVER; AREA COVERAGE; ICE SHEETS; CONNECTICUT RIVER; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA243431; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA243431

A quantitative theory of dynamic river ice breakup is not yet available. One of the essential components of such a theory is description of the ice motion near the breaking front. In this report we develop an analysis of this motion for a specific case that is consistent with observed data. The analysis is generalized by allowing the speed of the breaking front to vary, and the parameters of the ice motion that are obtained represent different dynamic breakup behaviors that have been described previously. The results of the analysis include (1) the hydraulic radius associated with the ice cover and the total ice acceleration as functions of time; (2) the equilibrium ice velocity as a function of bank resistance, and the ice velocity as a function of time for several initial and bank resistance conditions; (3) the time-varying bank resistance at the measurement location; and (4) the time of ice motion, ice velocity, ice acceleration, and the convergence of the moving ice with distance from the breaking front. The measure of ice convergence quantifies the loss of surface area by the sheet that is required for ice continuity, and distinguishes the types of dynamic breakup.