The geomorphological unit hydrograph - a critical review

The theory of the geomorphological unit hydrograph (GUH) is examined critic ally and it is shown chat the inherent assumption that the operation of the drainage network may be modelled by a corresponding network of linear rese rvoirs so restricts the instantaneous unit hydrograph (IUH) shape that the effects of further restrictions, reflecting the constraints imposed by the geomorphological laws of the channel network, cannot easily be identified. Without such identification, the geomorphological unit hydrograph theory is untestable and must remain only a plausible hypothesis providing an indica tion of a two-parameter IUH whose shape and scale factors must still be rel ated empirically to appropriate catchment characteristics.