Abstract

Hydrological nonstationarity has brought great challenges to the reliable application of conceptual hydrological models with time-invariant parameters. To cope with this, approaches have been proposed to consider time-varying model parameters, which can evolve in accordance with climate and watershed conditions. However, the temporal transferability of the time-varying parameter was rarely investigated. This paper aims to investigate the predictive ability and robustness of a hydrological model with time-varying parameter under changing environments. The conceptual hydrological model GR4J (Génie Rural à 4 paramètres Journalier) with only four parameters was chosen and the sensitive parameters were treated as functions of several external covariates that represent the variation of climate and watershed conditions. The investigation was carried out in Weihe Basin and Tuojiang Basin of Western China in the period from 1981 to 2010. Several sub-periods with different climate and watershed conditions were set up to test the temporal parameter transferability of the original GR4J model and the GR4J model with time-varying parameters. The results showed that the performance of streamflow simulation was improved when applying the time-varying parameters. Furthermore, in a series of split-sample tests, the GR4J model with time-varying parameters outperformed the original GR4J model by improving the model robustness. Further studies focus on more diversified model structures and watersheds conditions are necessary to verify the superiority of applying time-varying parameters.

Highlights

  • The conceptual hydrological models are simplified representations of the complex rainfall-runoff processes in the real world

  • The transferability of the model parameters between periods with different climate and watershed conditions is essential for reliable application of the hydrological models

  • The results show a significant downtrend for the annual Q and runoff ratio (RR) series, a slight downtrend for annual P series and uptrend for the potential evapotranspiration (PET) series in Weihe Basin

Read more

Summary

Introduction

The conceptual hydrological models are simplified representations of the complex rainfall-runoff processes in the real world. Great emphases are placed on the calibration of parameters to improve the performance of hydrological models. The ability to produce reliable predictions with the constant parameter set has been challenged under changing climate and watershed conditions [3,4,5,6,7,8]. The transferability of the model parameters between periods with different climate and watershed conditions is essential for reliable application of the hydrological models. Plenty of previous studies have revealed the fact that model parameters are strongly dependent on the data period with which the hydrological models are calibrated [9,10,11]. Loss of robustness and variation in model performance can be witnessed when the model parameters are inappropriately transferred [12]

Objectives
Methods
Results
Conclusion
Full Text
Published version (Free)

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 call