Author(s): Rhodri Howley; Yuntong She; Tadros Ghobrial
Linked Author(s): Yuntong She
Keywords:
Abstract: The winter regime of a northern river in an urban environment is often affected by many urban features such as municipal outfalls and bridges. The North Saskatchewan River (NSR) flowing through Edmonton, Alberta is one such example. Several previous studies on the NSR resulted in a relatively comprehensive database containing over a decade of ice related measurements. Analyses of these data have revealed several interesting and complex phenomena. The conditions at freeze-up are highly variable. Between the years 2009–2016, the degree days of freezing for the formation of a stable ice cover ranged between 50–130 °C•Days. The rate of ice front progression ranged between 3.7–8.6 km/day. The water level stage-up caused by the ice front passing a gauge station varied between 0.8–1.5 m, suggesting that both frontal progression through a juxtaposed mode and consolidation or shoving events can occur. There are multiple bridging locations within the study reach, which adds complexity to the freeze-up process. Urban outfalls including the Gold Bar Wastewater Treatment Plant (GBWTP) affects ice cover formation and can cause large open leads to form shortly after freeze-up. This study utilizes the University of Alberta’s River1D Ice Process model to explore these complex river ice processes during the 2010-11 winter season. The 29 km reach that is simulated includes discharges from the GBWTP. Simulation results are compared to the water surface elevation, ice front progression, surface pan concentration, border ice fraction, ice thickness, suspended frazil concentration, and water temperature data measured at several locations along the reach.
Year: 2020