IOS River Temperature Model
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The Fraser River Action Plan - or FRAP - is a joint venture by Environment Canada and the Department of Fisheries and Oceans (DFO) to protect, restore and clean up the Fraser River and its vast basin to ensure they stay healthy and productive. The Fraser River basin encompasses a rich diversity of fish, birds and wildlife, ecosystems, climates and landscapes, and is also home to nearly 2 million people - over 60% of BC's population. As one of the world's most productive water sheds, the Fraser Basin supports millions of salmon every year as they return to spawn in home streams of the Fraser River. Urban expansion and economic activities have seriously stressed the delicate ecological balance in the basin, polluting the rivers, damaging habitat and threatening salmon and other wildlife populations. One of the aims of FRAP is to rebuild fish stocks in the river by careful resource management through limits on fishing catches and targets for escapement (the number of spawners allowed to escape to ensure strong runs for the future). Part of this management includes collecting scientific data on which to base sound decisions, such as determining the impact of interior logging on salmon stocks, habitat and biodiversity; testing fish for contaminant levels and observing the effect of pulp mill effluent on juvenile salmon; and predicting the effects of global climate warming on fish and water flow. The IOS River Temperature Model (IOSRTM) was created from a need to understand the latter of these environmental effects.

Studies have shown that annual pre-spawning mortalities among summer run Fraser River sockeye salmon are linked to river temperatures (Gilhousen, 1990). Elevated temperatures tend to produce a higher number of pre-spawning mortalities due to a variety of biological effects such as increased metabolic activity resulting in rapid depletion of energy reserves. Elevated temperatures can also create conditions where incidence of infection is increased. To estimate in-river mortality of salmon during their migration, DFO biologists require spatially and temporally varying water temperature data. The idea of a model to predict the river temperatures was proposed in 1993, with the initial objectives to model the mainstem Fraser River from Hope to Prince George, and the mainstem Thompson River from the Fraser River confluence to Chase. The project proposal suggested that additional temperature models would be developed in the future for the major salmon migration routes through the Stuart, Horsefly, and Nicola Rivers.


The IOS River Temperature Model was originally created in 1993 by Triton Environmental Consultants Ltd. in the form of a contract to DFO. Although it was designed to be implemented on the Fraser River and associated tributaries, the model is general enough to be applied elsewhere. The model itself is a numerical temperature simulation program capable of predicting the riverwater temperature as a function of space and time given a variety of input variables. The temperature model relies on river flow and velocity data provided by the UBC Flow Model, a flow routing model developed at UBC by the Mountain Hydrology Group in the Department of Civil Engineering (Mountain Hydrology Group, 1994). The original Triton model was written in Microsoft FORTRAN for use on a PC, but was recoded in ANSI-C when it was transferred to IOS in 1994. In the summer of 1995, the model was run on an HP workstation at IOS to perform realtime predictions for DFO biologists. Currently (June, 1996), work is under way to improve the accuracy of the temperature model by using more sophisticated numerical techniques to solve the governing equations.

Papers and References

Foreman, M.G.G. et al. An Analysis of the 1995 Flow and Temperature Predictions for the Fraser and Thompson Rivers. Draft, last updated February 5, 1996.
PostScript file:

Foreman, M.G.G. et al. Flow and Temperature Models for the Fraser and Thompson Rivers. Submitted to Atmosphere-Ocean, April 30, 1996.
PostScript file:

Gilhousen, P. Prespawning mortalities of sockeye salmon in the Fraser River system and possible causal factors, Bulletin XXVI. International Pacific Salmon Fisheries Commission, pp 58, 1990.

Hollemans, P. Product Documentation: River Temperature Model, IOS Version 1.0. Unpublished, University of Victoria, Department of Physics and Astronomy, 1994.
PostScript file:

Mountain Hydrology Group. U.B.C. Flow Model Manual Version 2.0. Department of Civil Engineering, University of British Columbia, Canada. September, 1994.

Wiebe, E. Preliminary Results from the First Season of Operation of the Fraser River Temperature Prediction Project. Unpublished, University of Victoria, Department of Physics and Astronomy, 1995.
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Related Links
The University of Washington Columbia River Salmon Passage (CRiSP) is an interactive, multiple window program that helps managers of water, hydropower, fisheries and recreation see the impact of their decisions on fish populations in the Columbia River.

The Fraser River Action Plan (FRAP) is a joint Environment Canada/ Fisheries and Oceans program which aims to improve the long-term health and productivity of the Fraser River.

The UBC Flow Model was written by Water Resources, Hydrology & Hydraulics, Department of Civil Engineering, UBC.

The Integrated Fraser Salmon Model links salmon habitat management models and salmon fisheries management models into a spatially explicit planning tool. The project began in December 1994. This report was prepared in March 1995.

Salmon Life History and Habitat Modelling can replace the general Fraser River Biostandards model with detailed models of fish and habitat interactions.

The Pacific Biological Station homepage can also be used to get to the previous two links.

The Ocean Science and Productivity Division at IOS has more links related to oceanographic research.

The Yahoo category Yahoo:Science:Earth Sciences:Oceanography leads to many other oceanography sites.

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This page was written by Darren Duncan, copyright © June 25, 1996.
Last modified Fri Jun 28 11:36:42 PDT 1996 by

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