Author(s): Sean Boyd; Tadros Ghobrial; Mark Loewen
Linked Author(s): Tadros Ghobrial, Mark R. Loewen
Keywords: Ice blockages; Anchor ice; Supercooling; River ice processes
Abstract: The severe environmental conditions that generate ice blockages result in few quantitative studies of their formation and release conditions. The development of high-resolution remote sensors such as ice profiling sonars and temperature data loggers has enabled detailed measurements of river and intake conditions during the winter season. The Universite Laval River Ice Research Group monitored ice accumulations on the water intake for the municipal plant in Terrebonne, Quebec using sonar during the 2020-2021 winter season, along with meteorological and hydrological conditions. This study found that supercooling events with peak water temperature 0oC. This threshold correctly identified the start of the 7 accumulation events observed in this season, with 4 false positives. The net bed heat flux, defined as the sum of the turbulent heat flux at the water-ice interface and penetrating shortwave radiation, found to be < -20.0 W/m2 prior to all accumulation events with only 2 false positives. These threshold values could be used by operators to assess the risk of an ice blockage by forecasting or direct monitoring.
Year: 2024