NUMERICAL COMPUTATION OF RIVER ICE JAMS

A numerical model called RIVJAM has been developed to compute the configuration of and water levels caused by ice jams of the ''wide'' kind, under natural stream conditions and regardless of whether the jam has attained its full potential, known as equilibrium. Account of seepage flow through the voids of the jam enables predictions of grounding conditions to be made, in accord with observations. The model is applied to three case studies of ice jam events and found to perform satisfactorily. The various model coefficients fall within the expected ranges, with the exception of a parameter characterizing the intensity of seepage flow. More field data are needed to elucidate this matter.