Non-linearity in runoff routing models.

The basic assumptions in various readily available runoff routing models are examined. Case studies in the Little River catchment in Victoria and the Ord River catchment in Western Australia showed the form of catchment nonlinearity to be more complex than assumed by any of the available models. The implications for flood estimation of extreme floods, derivation of regional parameters and calibration techniques currently used in flood estimation by runoff routing are discussed. Basic guidelines in runoff routing model parameter selection are discussed. Notes a trend of different kc values for low and high flow conditions.