Model evaluation study demonstrates accurate prediction of thermal and chemical stratification in a subarctic pit lake, indicating its utility for long-term mine water management.
Key Points
Evaluate the ability of a one-dimensional hydrodynamic model (PitMod) to simulate long-term meromixis and stratification dynamics in a subarctic mine pit lake.
Calibrated the 1D hydrodynamic model (PitMod) using 9 years of continuous mooring data and 25 vertical profiles from the Colomac Zone 2 Pit in Northwest Territories, Canada.
Optimized model parameters for light extinction, wind drag coefficients, surface heat fluxes, and turbulent diffusion around the chemocline.
PitMod reproduced seasonal thermal dynamics in mooring records with an RMSE of 1.1°C, and profile stratification with an RMSE of 0.72°C for temperature and 0.007 g L⁻¹ for total dissolved solids (TDS).
Turbulent diffusion across the chemocline was weak but proved essential to capture the observed gradual broadening of the TDS gradient over time.