CentrEau and RIISQ (Réseau Inondations InterSectoriel du Québec) are glad to invite you to this webinar on the determination of flood levels in the presence of ice on the Chaudière River. This conference is based on the mandate given to Laval University, within the framework of a governmental flood hazard program initiated by the Ministère des Affaires Municipales et de l'Habitation (MAMH), which aims to evaluate the flood levels in the presence of ice on the Chaudière River.
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Specifically, ice jam modeling combined with historical ice jam observation data is used to determine ice jam flood levels. The recommended approach is to control a river hydraulic simulation model, specifically the HEC-RAS module, with an external script in Python to generate a Monte Carlo distribution (MOCA) of ice jam events along the study river section. Mechanical parameters such as friction angle, porosity, and critical shear stress velocities are also randomly assigned by the script within a bounded range. Physical and hydrological parameters assigned to each event are randomly selected based on a probability estimated from historical observations, i.e., calculated discharge at Sartigan, ice jam location, ice jam length, and freezing degree days (ice thickness). Flood ratings for the 2, 20, 100 and 350 year return periods are then determined using an empirical statistical Gringorten equation, followed by modulation for external factors not considered by MOCA. These ice-covered flood ratings are compared to the open-water ratings as determined by the conventional method.
Speaker: Jean-Robert Ladouceur, research professional at Laval University. These research projects are related to ice jams and flooding, hydraulic structures and ice control structures.
The presentation will be given in French.
