Data-fitted velocity profiles for ice-covered rivers

摘要

A two-layer analytical function for the vertical distribution of water velocities in ice-covered rivers is obtained from a multi-parameter regression analysis. This analysis uses velocity profiles measured from Canadian rivers covered with ice during the winter. The function contains a coefficient and two exponents. The exponents are associated with the frictional effects of the ice and riverbed, respectively, whereas the coefficient is related to the per-unit-width discharge. The ranges of values for the three parameters have been determined. It is shown that the two-layer function is satisfactory for describing the velocity distribution. Velocity profiles reconstructed using the parameter values are acceptable. Since it is difficult and expensive to obtain field measurements of water velocities from ice-covered rivers, the analytical function is a good alternative for such purposes as estimating winter discharges in such rivers. Also, the function can easily be incorporated into numerical models for simulating ice-covered river hydraulics.