An Automatic Parameter Calibration Method for the Tuw Model in Streamflow Modeling

Abstract

The accurate modelling of streamflow is highly significant for hydrological monitoring, water resource management, and climate change studies. Streamflow simulation with lumped hydrological models has been widely performed by researchers. However, the parameter calibration process is a major obstacle in these models. In the present study, a conceptual rainfall-runoff model (TUW model) was used to simulate streamflow in the sub-basin of the Upper Euphrates Basin during the time period 1991-2009. The Differential Evolution Optimization (DEoptim) algorithm were tested for the automatic parameter calibration of the lumped version of TUW model, in the study area. The model is calibrated using two objective function named and Nash–Sutcliffe efficiency (NSE) and Kling-Gupta Efficiency (KGE). Additionally, percent bias (PBias) was used to evaluate the performance of the model. For the objective function NSE, calibration and validation results indicated good agreement between observed and simulated streamflow data with NSE, 0.76 and 0.76 and KGE, 0.73 and 0.75 and PBias (%), -0.8 and -7.5, respectively. Similarly for KGE objective function, the calibration results produced a NSE of 0.71, KGE of 0.85, and PBias (%) of -0.9, while validation results revealed a NSE of 0.72, KGE of 0.84, and PBias (%) of -7.2. It can be concluded that the applicability of the DEoptim algorithm for the estimation of the parameters of the TUW model is confirmed by the case study. The findings of the study can serve as a guide for researchers and be useful in achieving watershed management goals.