Using the Distributed Hydrology Soil Vegetation Model and River Basin Model to predict stream discharge and temperature in the Horsefly watershed, British Columbia

Stream discharge and temperature are variables in the hydrological cycle that directly influence aquatic ecosystems. This study uses the Distributed Hydrology Soil Vegetation Model (DHSVM) and the River Basin Model (RBM) to simulate stream discharge and temperature in three basins of the Horsefly watershed, British Columbia, Canada. Using empirical meteorological and topographical data, we validated and assessed the performance of DHSVM and RBM. The DHSVM demonstrated satisfactory performance in simulating non-dammed streamflow, achieving adjusted R 2 values of 0.50 and 0.54, and Normalized Nash-Sutcliffe Efficiency (NNSE) values of 0.30 and 0.35 during calibration and validation, respectively. However, the model performed less well simulating a managed stream, likely due to coarse meteorological and soil input data. Conversely, the RBM performed well across all studied basins (Moffat: NNSE= 0.63, R 2 =0.57, Mckinley: NNSE= 0.79, R 2 = 0.93, McKusky and McKay: NNSE= 0.73, R 2 = 0.84). Despite data limitations, coupled DHSVM-RBM models predicted stream discharge well in unmanaged streams and stream temperature across the studied basins. Our work demonstrates the usefulness of these models to account for stream discharge and temperature under land cover and climate change scenarios, with linkages to aquatic ecosystem management.