Name
Hydrological modelling as an improvement on ECA-based methods for informing risk-based forest management
Date & Time
Tuesday, May 9, 2023, 1:45 PM - 2:00 PM
Description
Forest disturbance can affect the runoff regime of a watershed, altering the frequency, magnitude, and timing of peak flows as well as the duration of low flows. Equivalent Clearcut Area (ECA) calculations have been one of the primary tools used in watershed assessments to inform forest managers of the hydrologic response associated with existing or proposed forest disturbance. ECA analyses typically rely on broad regional assumptions, qualitative observations, and/or expert judgement, making it difficult to provide quantitative estimates of hydrologic change. Process-based hydrological models offer an improved approach to quantifying the effects of forest disturbance on hydrologic indicators of concern and to investigate cumulative effects of land cover and climate change, including at ungauged points of interest. A regionally calibrated hydrological model applied here uses land cover and weather data as inputs to simulate streamflow and other hydroclimatic variables; therefore, modifications to these input data such as harvest plans and/or climate change scenarios can be used to investigate how hydrologic conditions in the watershed may be altered. This workflow is demonstrated in Little Cayuse Creek in the West Kootenay region of British Columbia to investigate the cumulative effects of forest disturbance and climate change. Results are contrasted with ECA based outputs and emphasize that in addition to the amount of forest disturbance, watershed physical characteristics and the location of disturbance influence the hydrologic response. This approach provides forest managers with quantitative outputs that support risk-based forest management decisions and presents a substantial improvement over ECA-based methods.
Location Name
Ballroom
Full Address
Banff Park Lodge Resort Hotel & Conference Centre
201 Lynx St
Banff AB T1L 1K5
Canada
Abstract
Forest disturbance can affect the runoff regime of a watershed, altering the frequency, magnitude, and timing of peak flows as well as the duration of low flows. Equivalent Clearcut Area (ECA) calculations have been one of the primary tools used in watershed assessments to inform forest managers of the hydrologic response associated with existing or proposed forest disturbance. ECA analyses typically rely on broad regional assumptions, qualitative observations, and/or expert judgement, making it difficult to provide quantitative estimates of hydrologic change. Process-based hydrological models offer an improved approach to quantifying the effects of forest disturbance on hydrologic indicators of concern and to investigate cumulative effects of land cover and climate change, including at ungauged points of interest. A regionally calibrated hydrological model applied here uses land cover and weather data as inputs to simulate streamflow and other hydroclimatic variables; therefore, modifications to these input data such as harvest plans and/or climate change scenarios can be used to investigate how hydrologic conditions in the watershed may be altered. This workflow is demonstrated in Little Cayuse Creek in the West Kootenay region of British Columbia to investigate the cumulative effects of forest disturbance and climate change. Results are contrasted with ECA based outputs and emphasize that in addition to the amount of forest disturbance, watershed physical characteristics and the location of disturbance influence the hydrologic response. This approach provides forest managers with quantitative outputs that support risk-based forest management decisions and presents a substantial improvement over ECA-based methods.
Session Type
Breakout Session