Feb 1st, 2023 @ 12 pm: Ottawa SYP Water Talks – “Warming Cold Regions Groundwater” with Elise Devoie
Freeze/thaw processes play a fundamental role in cold regions hydrology. From infiltrability to groundwater flow, the quantity of ice in soils controls the movement of water through them. All physically-based groundwater models rely on a soil freezing characteristic curve (SFCC) to relate the unfrozen water content in a soil to its temperature. It is challenging and time consuming to measure an SFCC, and the choice of SFCC used in modelling is often based on numerical stability and computational expense, thus empirical SFCCs are often chosen. However the choice of SFCC can significantly impact simulations of streamflow, soil temperature, and ground ice. A case study of a homogenous, two-dimensional, hillslope underlain by permafrost is simulated in SUTRA-ICE, forced with time-dependant boundary conditions. The model is run with different widely used empirical SFCCs to examine the differences in model prediction. Results show that the choice of SFCC significantly affects permafrost evolution, active layer dynamics, and stream discharge from the model.