Regionalisation of hydrological model parameters in nested catchmentss

Abstract

A prediction in ungauged basins is one of the challenging tasks for a hydrologist of this century. Even though the physically based hydrological models can be the more appropriate in ungauged basins but data requirement limit the use. Conceptual hydrological models are simple and easy to use. But these model needs calibration before it can be used. Availability of data at all location in the basin limits the calibration of conceptual hydrological models. In this study, a calibration methodology is presented for discharge series limited condition using upstream and downstream data from nested catchment. It has been found that reasonable model parameters can be estimated for middle catchment using immediate upstream and downstream data. The regionalised parameter at the catchment outlet was tested at several locations inside the catchment to test the suitability of the outlet based model parameter for the interior location along the channel. It has been found that the model parameters obtained at the outlet of the catchment by regionalisation methods can be applied to the neighbouring points along the channel. A conceptual hydrological model, HBV-IWS was used for on upper Neckar catchment to demonstrate the methodology.