The Äshèyi Chu/Aishihik River – River Ice Model – YukonU Research Centre’s RIMA

 
This project was funded by Crown-Indigenous Relations and Northern Affairs Canada’s Climate Change Preparedness in the North Program (CIRNAC – CCPN). It extended from 2021 to 2025. Partners on this project include Champagne and Aishihik First Nations (CAFN), Yukon Energy Corporation (YEC), and the Government of Yukon – Department of the Environment (YG – ENV). The University of Alberta (UofA), Department of Civil and Environmental Engineering, was also actively involved in the project by developing a distinct river ice model using the River 1D hydrodynamic environment developed at UofA.
Project description
The flow of the Äshèyi Chu has been controlled since the 1970s for hydroelectric production. The morphology of the river has undergone significant change since then and winter flooding has become recurrent in recent years, negatively impacting the environment and CAFN lands. The objective of this project was to develop a model that would simulate ice processes and winter water levels along the Äshèyi Chu in order to inform future Aishihik Generating Station (AGS) flow management in a perspective of reducing ice-related flooding and promoting a stabilization of the channel.
 
The Climate Change Research (CCR) group – Hydrology team designed a physics-based empirical river ice model using Microsoft Excel. The development and calibration of the model were informed by observations (remote cameras) and data (aquatic and air temperature sensors) obtained from a monitoring program implemented by Morisson Hershfield (now Stantec) over several consecutive winters. The vision behind the River Ice Model for the Äshèyi Chu (RIMA) was that it should remain simple to operate, rely on readily available input parameters, and simulate complex but realistic ice processes as well as ice-affected water level variations. This was completed by dividing the river into six reaches, using a daily time, and performing sequential calculation steps from upstream to downstream and from October to April.
 
As a complement to the model, with its 200+ parameters, 100+ spreadsheet columns, RIMA was also translated into a conceptual form, which includes a list of seasonal considerations to operate AGS while reducing ice-induced water levels.
Project team
  • Benoit Turcotte, Senior Research Professional – Hydrology and modelling
  • Stephanie Saal, Research Professional – Drone pilot and GIS analyses
  • Avery Zammit, Project Officer
  • Brian Horton, Scientific Director
  • Yuntong She, Professor, University of Alberta
  • Mark Loewen, Professor, University of Alberta
  • Heyu Fang, PhD student, University of Alberta
Funder
  • CIRNAC - Climate Change Preparedness in the North
Publications

Turcotte, B., Zammit, A., 2026. The Äshèyi Chu/Aishihik River – River Ice Model YukonU Research Centre’s RIMA – Low-flow update version. Presented to the Champagne and Aishihik First Nations, The Government of Yukon, and Yukon Energy. YukonU Research Centre, 14p.

Turcotte, B., Saal, S., Horton, B., Zammit, A., 2025. The Äshèyi Chu/Aishihik River - River Ice Model YukonU Research Centre’s RIMA. Presented to the Champagne and Aishihik First Nations, The Government of Yukon, and Yukon Energy. YukonU Research Centre, 100p.

Saal, S., Turcotte, B., Girard, M., Dubnick, A., 2024. A logic-driven assessment to refine SAR-based river ice classifications. 27th IAHR International Symposium on Ice. Book of Proceedings, Vol. 2, 40-50. Gdańsk, Poland. ISBN: 978-83-7348-925-7.