A volume law for specification of linear channel storage for estimation oflarge floods

A method of estimating large floods using a linear storage-routing approach is presented. The differences between the proposed approach and those trad itionally used are (1) that the flood producing properties of basins are re presented by a linear system, (2) the storage parameters of the distributed model are determined using a volume law which, unlike other storage-routin g models, accounts for the distribution of storage in natural basins, and ( 3) the basin outflow hydrograph is determined analytically and expressed in a succinct mathematical form. The single model parameter is estimated from observed data without direct fitting, unlike most traditionally used metho ds. The model was tested by showing it could reproduce observed large flood s on a number of basins. This paper compares the proposed approach with a t raditionally used storage routing approach using observed hood data from th e Hacking River basin in New South Wales, Australia. Results confirm the us efulness of the proposed approach for estimation of large floods.