Ice-jam flood risk assessment and mapping

In northern regions, river ice- jam flooding can be more severe than open-water flooding causing property and infrastructure damages, loss of human life and adverse impacts on aquatic ecosystems. Very little has been performed to assess the risk induced by ice-related floods because most risk assessments are limited to open-water floods. The specific objective of this study is to incorporate ice-jam numerical modelling tools (e.g. RIVICE, Monte-Carlo simulation) into flood hazard and risk assessment along the Peace River at the Town of Peace River (TPR) in Alberta, Canada. Adequate historical data for different ice-jam and open-water flooding events were available for this study site and were useful in developing ice-affected stage-frequency curves. These curves were then applied to calibrate a numerical hydraulic model, which simulated different ice jams and flood scenarios along the Peace River at the TPR. A Monte-Carlo analysis was then carried out to acquire an ensemble of water level profiles to determine the 1:100-year and 1:200-year annual exceedance probability flood stages for the TPR. These flood stages were then used to map flood hazard and vulnerability of the TPR. Finally, the flood risk for a 200-year return period was calculated to be an average of $32/m(2)/a ($/m(2)/a corresponds to a unit of annual expected damages or risk). Copyright (c) 2016 John Wiley & Sons, Ltd.