Resource managers need more accurate information about how cold-water habitats for fish will change in the future.
Researchers used a physical process-based model to investigate the potential impact of climate change on streamflow and water temperature in the Snoqualmie and Siletz watersheds in Washington and Oregon. The model was calibrated with remotely sensed, spatially continuous water temperature data to simultaneously predict patterns in space and time at high resolution across the two stream networks. The process-based model projected greater changes in summer maximum water temperatures by the year 2080 for the mixed-rain-snow Snoqualmie watershed—due to loss of snowpack and reduction in summer flow—than for the rain-dominated Siletz watershed. The model also projected higher spatial heterogeneity in water temperature compared to a widely used statistical model. Results suggested that salmonids may have fewer summertime cold-water habitats in both watersheds. Authors conclude that this model is especially well-suited for predicting conditions in areas with limited in-stream temperature data.
Lee, S., Fullerton, A.H., Sun, N., Torgersen, C.E., 2020, Projecting spatiotemporally explicit effects of climate change on stream temperature: A model comparison and implications for coldwater fishes: Journal of Hydrology, v. 588, p. 125066. https://doi.org/10.1016/j.jhydrol.2020.125066