PROPHECY, REALITY AND UNCERTAINTY IN DISTRIBUTED HYDROLOGICAL MODELING

Difficulties in defining truly mechanistic model structures and diffic ulties of model calibration and validation suggest that the applicatio n of distributed hydrological models is more an exercise in prophecy t han prediction. One response to these problems is outlined in terms of a realistic assessment of uncertainty in hydrological prophecy, toget her with a framework (GLUE) within which such ideas can be implemented . It is suggested that a post-modernistic hydrology will recognise the uncertainties inherent in hydrological modelling and will focus atten tion on the value of data in conditioning hydrological prophecies.