Unit hydrograph characterization of flow regimes leading to streamflow estimation in ungauged catchments (regionalization)

The IHACRES rainfall–streamflow modelling approach provides a powerful set of techniques for assisting with parametrically efficient regionalization of streamflow response characteristics (unit hydrograph and loss module parameters) from inputs of rainfall, evaporation surrogates and physical catchment descriptor data. Recent work has indicated where further improvements can be made to the model structure and its model parameter estimation procedure, for regionalization work. IHACRES could, therefore, form a useful component of PUB, whence its continuing development would benefit greatly from application to PUB data sets and exposure to the wider PUB community. In order to register IHACRES at the Brasilia PUB kick-off meeting, and to seek comments as to how it might best contribute to the PUB Decade, this paper has the following objectives: (1) to outline the IHACRES approach and techniques, and their roles in assisting with regionalization; (2) to discuss the relevance of IHACRES within PUB; and (3) to propose an IHACRES component of PUB.