Determination of ice jam thickness-A new approach

In winter, rivers in cold regions often experience flood disasters resulted from ice jams or ice dams. Investigations of the variation of ice jam thickness and water level during an ice jammed period are not only a practical need for ice prevention to avoid disaster and plan water resource, but also essential for the development of any mathematical model for predicting the evolution of ice jam. So far, some equations based on the energy equation have been proposed to describe the relationship between ice jam thickness and water level. However, in the derivation of these equations, the local head loss coefficient at the ice jam head and the riverbed slope factor were neglected. Obviously, those reported equations cannot be used to preciously describe the flow energy equation with ice jams and accurately calculate the ice jam thickness and water level. In the present study, a more comprehensive theoretical model for hydraulic calculation of ice jam thickness has been derived by considering important and essential factors including riverbed slope and local head loss coefficient at the ice jam head. Furthermore, based on the data collected from laboratory experiments of ice jam accumulation, the local head loss coefficient at the ice jam head has been calculated, and the empirical equation for calculating the local head loss coefficient has been established by considering flow Froude number and the ratio of ice discharge to flow discharge. The results of this study not only provide a new reference for calculating ice jam thickness and water level, but also present a theoretical basis for accurate CFD simulation of ice jams.