Hydrology and Earth System Sciences
www.hydrol-earth-syst-sci.net
1027-5606
1607-7938
11
6
2007
10.5194/hess-11-1797-2007
http://www.hydrol-earth-syst-sci.net/11/1797/2007/
http://www.hydrol-earth-syst-sci.net/11/1797/2007/hess-11-1797-2007.html
http://www.hydrol-earth-syst-sci.net/11/1797/2007/hess-11-1797-2007.pdf
1797
1809
2007-11-22
Soft combination of local models in a multi-objective framework
F. Fenicia
D. P. Solomatine
H. H. G. Savenije
P. Matgen
Public Research Center – Gabriel Lippmann, Luxembourg
Water Resources Section, Faculty of Civil Engineering and Geosciences, Delft Univ. of Technology, The Netherlands
UNESCO-IHE Institute for Water Education, Delft, The Netherlands
Conceptual hydrologic models are useful tools as they provide an
interpretable representation of the hydrologic behaviour of a catchment.
Their representation of catchment's hydrological processes and physical
characteristics, however, implies a simplification of the complexity and
heterogeneity of reality. As a result, these models may show a lack of
flexibility in reproducing the vast spectrum of catchment responses. Hence,
the accuracy in reproducing certain aspects of the system behaviour may be
paid in terms of a lack of accuracy in the representation of other aspects.
<br><br>
By acknowledging the structural limitations of these models, we propose a
modular approach to hydrological simulation. Instead of using a single model
to reproduce the full range of catchment responses, multiple models are
used, each of them assigned to a specific task. While a modular approach has
been previously used in the development of data driven models, in this study
we show an application to conceptual models.
<br><br>
The approach is here demonstrated in the case where the different models are
associated with different parameter realizations within a fixed model
structure. We show that using a "composite" model, obtained by a
combination of individual "local" models, the accuracy of the simulation
is improved. We argue that this approach can be useful because it partially
overcomes the structural limitations that a conceptual model may exhibit.
The approach is shown in application to the discharge simulation of the
experimental Alzette River basin in Luxembourg, with a conceptual model that
follows the structure of the HBV model.
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