Dry Weather Flow Yield as a geological index

A residual flow diagram provides a snapshot of the flow throughout a river system in terms of its natural and artificial components. Under dry weather flow conditions, the natural component, if expressed in terms of yield per unit area is directly related to catchment geology and as such, can be used as an index of catchment behaviour. Examples are given of the successful application of Dry Weather Flow Runoff Yield as a geological index in methods of flow frequency curve estimation and in the simulation of storm runoff from rainfall.