||Moore, RD, Nelitz, M and Parkinson, E. 2013. Empirical modelling of maximum weekly average stream temperature in British Columbia, Canada, to support assessment of fish habitat suitability. Canadian Water Resources Journal 38: 135-147.
|Abstract/Description or Keywords
||The objective of this study was to characterize the spatial variability of stream thermal regimes in British Columbia, Canada, with the specific goal of developing a predictive model to assist in provincial-scale assessment of fish habitat. It is part of a broader study to develop an approach to support the designation of “Temperature Sensitive Streams”, particularly in relation to the potential effects of forest harvesting and climate change. Stream temperature data were collected from researchers, consultants and government agencies. After checking for data quality, the annual maximum of a seven-day running average of mean daily water temperature (MWAT) was extracted for each station-year. A multiple regression model for the mean MWAT for each station was fitted for stations having basin areas between 1 and 104 km2. Predictor variables included the logarithm of catchment area, normal July–August air temperature for the location, the square root of the percentage of glacier cover in the catchment, the square root of the percentage of lake cover in the catchment, the mean catchment elevation, channel slope, a coefficient related to intensity of the mean annual flood, and the deviation of July–August air temperature during the monitoring year(s) from the average during a reference period. Model coefficients were consistent with the physical processes known to govern stream temperature. The standard deviation of prediction errors from a 10-fold cross-validation was 2.1°C. Lack of information on riparian shading is a likely source of a significant portion of the prediction error. The model can be used to provide an initial prediction of stream temperature regime for fish habitat assessment, as well as to provide first-order estimates of the sensitivity of MWAT to climatic warming and glacier retreat.