Evaluation of long range summer forecasts of lower Fraser River discharge and temperature conditions

Extreme temperature and discharge conditions in the Fraser River adversely affect adult sockeye salmon migration success. Current fisheries management practices adjust harvest plans based on predicted summer temperature and discharge values. Therefore, the development of long range (~1 to 4 months) forecasts of environmental conditions will aid in pre-season harvest planning. This report evaluated several models used to make long range forecasts of summer conditions. Fraser River sockeye salmon (Oncorhynchus nerka) run-timing groups were used as a case study to illustrate model performance. Most models were best-fit using simple, or multiple, linear regressions. Recommendations of the most appropriate models were made based on model fit, forecast uncertainty and the timing of data availability.--Document.

Open All Close All

type

http://www.w3.org/1999/02/22-rdf-syntax-ns#type

about

http://schema.org/about

contributor

http://schema.org/contributor

creator

http://schema.org/creator

http://worldcat.org/entity/person/id/2638718693

description

http://schema.org/description

"Extreme temperature and discharge conditions in the Fraser River adversely affect adult sockeye salmon migration success. Current fisheries management practices adjust harvest plans based on predicted summer temperature and discharge values. Therefore, the development of long range (~1 to 4 months) forecasts of environmental conditions will aid in pre-season harvest planning. This report evaluated several models used to make long range forecasts of summer conditions. Fraser River sockeye salmon (Oncorhynchus nerka) run-timing groups were used as a case study to illustrate model performance. Most models were best-fit using simple, or multiple, linear regressions. Recommendations of the most appropriate models were made based on model fit, forecast uncertainty and the timing of data availability.--Document."@en
"Extreme temperature and discharge conditions in the Fraser River adversely affect adult sockeye salmon migration success. Current fisheries management practices adjust harvest plans based on predicted summer temperature and discharge values. Therefore, the development of long range (~1 to 4 months) forecasts of environmental conditions will aid in pre-season harvest planning. This report evaluated several models used to make long range forecasts of summer conditions. Fraser River sockeye salmon (Oncorhynchus nerka) run-timing groups were used as a case study to illustrate model performance. Most models were best-fit using simple, or multiple, linear regressions. We quantified the uncertainty in the temperature and discharge forecasts arising from uncertainty in the model structure, and, where applicable, uncertainty in the predictor variable. Predictor variables include winter precipitation anomalies, spring and summer air temperature anomalies, water volume forecasts, and historic trends in water and air temperatures. Temperature forecast models performed comparably, and consistently predicted summer river temperatures with a coefficient of variation of less than 8% and an approximate standard deviation of 1°C. The precision of discharge forecasts deteriorated throughout the summer, and there was a trade-off between the availability of the forecast method and the precision of the results. In general, increasing the number of days used to calculate the predicted means led to small improvements in model fit, however there was only modest improvement going from 19-day to 31-day means. Recommendations of the most appropriate models were made based on model fit, forecast uncertainty and the timing of data availability."

name

http://schema.org/name

"Evaluation of long range summer forecasts of lower Fraser River discharge and temperature conditions"@en
"Evaluation of long range summer forecasts of lower Fraser River discharge and temperature conditions"

workExample

http://schema.org/workExample