Discriminant analysis of the freeze-up and break-up conditions in the Inner Mongolia Reach of the Yellow River

This study divided the total storage potential in a natural channel into the ice production volume and the water storage capacity volume. Thermal factors, hydraulic processes, topography, and ice formation were selected to derive a discriminant equation for freeze-up and break-up conditions in the Inner Mongolia Reach of the Yellow River. The trends observed from data for the freeze-up dates, break-up dates, and total frozen days from 2017 to 2020 conform to the principle that the river is gradually frozen from the downstream to the upstream and later thawed from the upstream to the downstream. The number of frozen days in the downstream is greater than in the upstream. Results indicate that freeze-up typically occurs when the proportion of ice in the channel is relatively high. Higher temperatures and greater discharges are required to facilitate the break-up of the river when the equilibrium ice thickness is greater. This study can provide a theoretical basis and framework for establishing an accurate freeze-up and break-up forecast model to prevent and mitigate ice-induced disasters. HIGHLIGHTS Total channel storage potential can be divided into ice production amount and water storage capacity under the ice cover in winter.; Thermodynamic factors, hydraulic parameters, topography, and ice production impact a river's freeze-up and break-up processes.; Empirical equations can assist in determining whether freeze-up/break-up will occur.;