Author(s): Karl-Erich Lindenschmidt; Mohammad Ghoreishi; Ali Khan

Linked Author(s): Karl-Erich Lindenschmidt

Keywords: Frazil ice; Ice-jam flood hazard and risk; Flood hazard assessment and risk mapping; Stochastic modelling framework

Abstract:

Although ice-jam flooding in northern rivers is generally more severe during ice-cover breakup in spring, ice jams during river freeze-up and mid-winter breakup can also impose high flood hazard in some rivers, particularly those in regions with a maritime climate (e. g. Atlantic Canada). In this paper, we numerically simulate ice-jam flood hazard and carried out the flood mapping of a high ice-jam flood risk community along the Exploits River in Newfoundland where the most severe floods occur from ice jams formed during river freezing. A stochastic modelling approach was used to simulate the processes of ice-jam formation and flooding along the river during freeze-up. This approach uses a deterministic river ice hydraulics model that is run repeatedly within a Monte-Carlo framework. Input values for the parameters and boundary conditions were chosen randomly from frequency distributions. An ensemble of backwater levels was produced from which profiles of exceedance probabilities were calculated. The water level elevations are extrapolated into the floodplain to determine flood depths. This approach is a new method to estimate ice-jam flood hazard and risk stemming from river freezing.

DOI:

Year: 2024