HYDRAULIC MODELLING TO ASSESS RAMPING EFFECTS OF RUN-OF-RIVER HYDROELECTRIC PROJECT

摘要

Globally, hydroelectric power is becoming increasingly favoured as a reliant source of energy. In Canada, particularly the province of British Columbia, hydroelectric generation is the predominant form of electric generation with small hydroelectric generation projects known as "run-of-river" projects becoming increasingly popular. While these types of projects are less intrusive than large scale dams and reservoirs that are typically associated with hydroelectric, they can still pose environmental risks. The ramping rate at which water is diverted during start-up and shut-down causes fluctuating water levels in downstream sections of the watercourse. The rates at which these fluctuations occur create gains and losses in wetted width and depth which can create isolated pools at stream margins. Rapid changes to flow as a result of run-of-river operations can cause dewatering of habitat and fish stranding. Fitzsimmons Creek, located in Whistler, British Columbia, Canada, was modelled using a 1-D hydraulic computer model to determine if the effect of different ramping rates could be accurately predicted without the need for instream field testing and observations. Geometric and flow data previously collected for other purposes was adapted to create a tool to predict the change in stage and subsequently the likelihood of fish stranding caused by run-of-river projects. While the model was unable to replicate the exact lag times and the change in stage compared to field measurements, the study has shown that a cost effective management tool can be created based on existing data to assist environmental managers assess the impacts of ramping in run-of-river hydroelectric projects.