River routing at the continental scale: use of globally-available data andan a priori method of parameter estimation

Two applications of a river routing model based on the observed river netwo rk and a linearised solution to the convective-diffusion equation are prese nted. One is an off-line application to part of the Amazon basin (catchment area 2.15 M km(2)) using river network data from the Digital Chart of the World and GCM-generated runoff at a grid resolution of 2.5 degrees latitude and 3.75 degrees longitude. The other application is to the Arkansas(409,0 00 km(2)) and Red River (124,400 km(2)) basins as an integrated component o f a macro-scale hydrological model, driven by observed meteorology and oper ating on a 17 km grid. This second application makes use of the US EPA reac h data to construct the river network. In both cases, a method of computing parameter values a priori has been applied and shows some success, althoug h some interpretation is required to derive 'correct' parameter values and further work is needed to develop guidelines for use of the method. The app lications, however, do demonstrate the possibilities for applying the routi ng model at the continental scale, with globally-available data and a prior i parameter estimation, and its value for validating GCM output against obs erved flows.