Scaling aspects of river flow routing

Scaling aspects of river flow routing are studied by comparing two flow rou ting schemes, one designed for use in coupled general circulation models (G CMs) and operated at large spatial scales (similar to 350 km), and the othe r designed for use in typical hydrological applications at small spatial sc ales (similar to 25 km). The same runoff data are used as input into the tw o routing schemes, and comparisons are made between mean annual, mean month ly and daily streamflow simulated at four locations within the Mackenzie Ri ver Basin. The results suggest that for the purpose of realistically modell ing monthly streamflow at the mouth of the rivers in GCMs, flow routing at large spatial scales gives similar results. However, the amplitude of the a nnual streamflow cycle is slightly but characteristically larger, when rout ing is performed at large spatial scales. Flow routing at large spatial sca les also results in overestimation of high flows, while low flows are under estimated. Copyright (C) 2001 John Wiley & Sons, Ltd.