Applying a climatic change scenario to a semi-distributed watershed model

Atmospheric general circulation models (CGMs) predict major changes in the earth’s climate due to an expected doubling of atmospheric greenhouse gases such as CO2. Watershed models have been used to estimate the effects of the changed climate on water resources but these models have generally assumed that the watershed itself will remain unchanged. It is more likely that a changing climate will change the distribution and the transpiration efficiency of vegetation. A semi-distributed hydrological model was applied to a watershed in the Rocky Mountains of British Columbia. The watershed was divided into a number of sub-basins and each sub-basin was divided into land-use zones. The paper discusses the methods available for linking the output of the GCM to the watershed model and discusses the results of the application in terms of the model responses.