Flood frequency estimation by continuous simulation (with likelihood baseduncertainty estimation)

A continuous simulation methodology, which incorporates the quantification of modelling uncertainties, is used for flood frequency estimation. The met hodology utilises the rainfall-runoff model TOPMODEL within the uncertainty framework of GLUE. Long return period estimates are obtained through the c oupling of a stochastic rainfall generator with TOPMODEL. Examples of appli cations to four gauged UK catchments are provided. A comparison with a trad itional statistical approach indicates the suitability of the methodology a s an alternative technique for flood frequency estimation. It is suggested that, given an appropriate choice of rainfall-runoff model and stochastic r ainstorm generator, the basic methodology can be adapted for use in many ot her regions of the world.