Evaluation of different calibration strategies for large scale continuous hydrological modelling

Abstract

Abstract. For the analysis of climate impact on flood flows and flood frequency in macroscale river basins, hydrological models can be forced by several sets of hourly long-term climate time series. Considering the large number of model units, the small time step and the required recalibrations for different model forcing an efficient calibration strategy and optimisation algorithm are essential.This study investigates the impact of different calibration strategies and different optimisation algorithms on the performance and robustness of a semi-distributed model. The different calibration strategies were (a) Lumped, (b) 1-Factor, (c) Distributed and (d) Regionalisation. The latter uses catchment characteristics and estimates parameter values via transfer functions. These methods were applied in combination with three different optimisation algorithms: PEST, DDS, and SCE. In addition to the standard temporal evaluation of the calibration strategies, a spatial evaluation was applied. This was done by transferring the parameters from calibrated catchments to uncalibrated ones and validating the model performance of these uncalibrated catchments. The study was carried out for five sub-catchments of the Aller-Leine River Basin in Northern Germany.The best result for temporal evaluation was achieved by using the combination of the DDS optimisation with the Distributed strategy. The Regionalisation method obtained the weakest performance for temporal evaluation. However, for spatial evaluation the Regionalisation indicated more robust models, closely followed by the Lumped method. The 1-Factor and the Distributed strategy showed clear disadvantages regarding spatial parameter transferability. For the parameter estimation based on catchment descriptors as required for ungauged basins, the Regionalisation strategy seems to be a promising tool particularly in climate impact analysis and for hydrological modelling in general.

Evaluation of the Parameter Sensitivities of a Coupled Land Surface Hydrologic Model at a Critical Zone Observatory

“…To decrease the dimensionality of parameter space in Flux-PIHM, the single global calibration multiplier method (also called the one-factor method; Pokhrel and Gupta 2010;Wallner et al 2012) is adopted. The global calibration multiplier, that is, the calibration coefficient, acts on the corresponding soil-or vegetation-related parameters for all soil or vegetation types.…”

Design hydrograph estimation in small and fully ungauged basins: a preliminary assessment of the EBA4SUB framework

“…For a detailed description of the Aller‐Leine river basin, please refer to Wallner et al . (, ). IDF curves for different return periods T r are available, and maximum monthly peak discharges have been observed from 1951 to 2005 thanks to the KOSTRA‐DWD Program ().…”

“…The flatland dominating the northern part of the catchment is characterised by sandy soils, porous quaternary aquifers and heath and moor vegetation. For a detailed description of the Aller-Leine river basin, please refer to Wallner et al (2012Wallner et al ( , 2013. IDF curves for different return periods Tr are available, and maximum monthly peak discharges have been observed from 1951 to 2005 thanks to the KOSTRA-DWD Program (2000).…”

Non-stationary hydrological model parameters: a framework based on SOM-B

“…In regionalization studies, a common procedure is the one‐step approach, where relations of model parameters and catchment descriptors are trained simultaneously for several donor catchments (Fernandez et al ., ; Hundecha and Bárdossy, ; Samaniego et al ., ; He et al ., ; Wallner et al ., ). This concept ensures that similar catchments will have similar model parameters and can be easily adapted for the temporal transfer of hydrological model parameters.…”