Abstract
Abstract. It has been demonstrated that the application of time-varying hydrological-model parameters based on dynamic catchment behavior significantly improves the accuracy and robustness of conventional models. However, the fundamental problems for calibrating dynamic parameters still need to be addressed. In this study, five calibration schemes for dynamic parameters in hydrological models were designed to investigate the underlying causes of poor model performance. The five schemes were assessed with respect to the model performance in different flow phases, the transferability of the dynamic parameters to different time periods, the state variables and fluxes time series, and the response of the dynamic parameter set to the dynamic catchment characteristics. Furthermore, the potential reasons for the poor response of the dynamic parameter set to the catchment dynamics were investigated. The results showed that the underlying causes of poor model performance included time-invariant parameters, “compensation” among parameters, high dimensionality and abrupt shifts in the parameters. The recommended calibration scheme exhibited good performance and overcame these problems by characterizing the dynamic behavior of the catchments. The main reason for the poor response of the dynamic parameter set to the catchment dynamics may be the poor convergence performance of the parameters. In addition, the assessment results of the state variables and fluxes and the convergence performance of the parameters provided robust indications of the dominant response modes of the hydrological models in different sub-periods or catchments with distinguishing catchment characteristics.
Highlights
IntroductionHydrological modeling is an essential tool for understanding the hydrological processes of a catchment and forecasting streamflow (Liu et al, 2015, 2018; Turner et al, 2017; Delorit et al, 2017; Fenicia et al, 2014, 2018; Hublart et al, 2016; Höge et al, 2018; Sarrazin et al, 2016; Wi et al, 2015; Herman et al, 2013; Wagener et al, 2001, 2003; Madsen, 2000; Osuch et al, 2019; Zhang et al, 2019)
Control scheme 4 is designed to investigate potential problems caused by abrupt changes in the parameters. These control schemes are assessed as follows: (1) the model performance is assessed at very low, low, medium, high and very high phases of flow, and the transferability of the dynamic parameter set to different time periods is determined; (2) the state variable and flux time series and their changes between two consecutive sub-periods are evaluated; and (3) the response of the dynamic parameter set to the dynamic catchment characteristics is evaluated
The potential reasons for the poor response of the dynamic parameter set to the catchment dynamics were discussed
Summary
Hydrological modeling is an essential tool for understanding the hydrological processes of a catchment and forecasting streamflow (Liu et al, 2015, 2018; Turner et al, 2017; Delorit et al, 2017; Fenicia et al, 2014, 2018; Hublart et al, 2016; Höge et al, 2018; Sarrazin et al, 2016; Wi et al, 2015; Herman et al, 2013; Wagener et al, 2001, 2003; Madsen, 2000; Osuch et al, 2019; Zhang et al, 2019). The reasons are that a unique parameter set optimized by hydrological models only represents the average hydrological processes, which do not accurately represent the dynamic response modes of the catchments processes (Pathiraja et al, 2018; Fowler et al, 2018; Zhao et al, 2017; Kim and Han, 2017; Golmohammadi et al, 2017; Delorit et al, 2017; Chen et al, 2017). To investigate the problems caused by time-invariant parameters, a control scheme, i.e., scheme 1, Published by Copernicus Publications on behalf of the European Geosciences Union
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
