Comparison of spectral and time domain calibration methods for precipitation‐discharge processes |
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| Authors: | Jan J Quets Gabriëlle J M De Lannoy Valentijn R N Pauwels |
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| Institution: | Laboratory of Hydrology and Water Management, Ghent University, Coupure links 653, B‐9000 Ghent, Belgium |
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| Abstract: | Hydrological model parameter estimation is an important aspect in hydrologic modelling. Usually, parameters are estimated through an objective function minimization, quantifying the mismatch between the model results and the observations. The objective function choice has a large impact on the sensitivity analysis and calibration outcomes. In this study, it is assessed whether spectral objective functions can compete with an objective function in the time domain for optimization of the Soil and Water Assessment Tool (SWAT). Three empirical spectral objective functions were applied, based on matching (i) Fourier amplitude spectra, (ii) periodograms and (iii) Fourier series of simulated and observed discharge time series. It is shown that most sensitive parameters and their optimal values are distinct for different objective functions. The best results were found through calibration with an objective function based on the square difference between the simulated and observed discharge Fourier series coefficients. The potential strengths and weaknesses of using a spectral objective function as compared to utilising a time domain objective function are discussed. Copyright © 2010 John Wiley & Sons, Ltd. |
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| Keywords: | calibration discharge Fourier analysis objective function sensitivity analysis spectral calibration equifinality |
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