450
E.T. Engman and G.A. Schultz
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Fig. 20.1. TIlustration of the various components in a sequential data base necessary to support
parameter estimation for a distributed hydrological model. (After Schultz, 1993)
resolution in space and time. How can we truly believe a so-called physically
based, distributed model that supposedly accounts for all the processes but is
driven only by rainfall and validated only by a measured hydrograph?
The data issues have been addressed in Opportunities in the Hydrological Sciences (NRC, 1991) and base its discussions on the premise that "hydrologic science is currently data limited". The report discusses the general aspects of data
needs conceding that traditionally hydrological data have been collected to address