ESTIMATION OF DAILY SPACE-TIME PRECIPITATION SERIES FOR MACROSCALE HYDROLOGICAL MODELING

An important problem in modelling macroscale basins, especially for sp arsely observed regions, is the lack of precipitation information. Alt ernatives to using straightforward interpolated surface observations i nclude the utilization of more advanced interpolation techniques and t he use of additional precipitation information from atmospheric models . Conventional and geostatistical methods are applied for optimal inte rpolation and assimilation of observed and model precipitation. Variou s time-series of daily areal precipitation distributions are produced and compared using not only an internal precipitation validation, but also an objective verification based on stream flow simulations. The M ackenzie River Basin in north-western Canada is used as the study area and hydrological simulations are carried out with the model SLURP. It was found that better interpolation techniques and the use of combine d precipitation data can improve the hydrological simulations and that the enhancements are related to the relative size of the simulation u nits used. (C) 1998 John Wiley & Sons, Ltd.