Does the Complexity of Evapotranspiration and Hydrological Models Enhance Robustness?

Abstract

Abstract:In this study, five hydrological models of increasing complexity and 12 Potential Evapotranspiration (PET) estimation methods of different data requirements were applied in order to assess their effect on model performance, optimized parameters, and robustness. The models were applied over a set of 10 catchments that are located in South Korea. The Shuffled Complex Evolution-University of Arizona (SCE-UA) algorithm was implemented to calibrate the hydrological models for each PET input while considering similar objective functions. The hydrological models' performance was satisfactory for each PET input in the calibration and validation periods for all of the tested catchments. The five hydrological models' performance were found to be insensitive to the 12 PET inputs because of the SCE-UA algorithm's efficiency in optimizing model parameters. However, the five hydrological models' parameters in charge of transforming the PET to actual evapotranspiration were sensitive and significantly affected by the PET complexity. The values of the three statistical indicators also agreed with the computed model evaluation index values. Similarly, identical behavioral similarities and Dimensionless Bias were observed in all of the tested catchments. For the five hydrological models, lack of robustness and higher Dimensionless Bias were seen for high and low flow as well as for the Hamon PET input. The results indicated that the complexity of the hydrological models' structure and the PET estimation methods did not necessarily enhance model performance and robustness. The model performance and robustness were found to be mainly dependent on extreme hydrological conditions, including high and low flow, rather than complexity; the simplest hydrological model and PET estimation method could perform better if reliable hydro-meteorological datasets are applied.

Effectiveness of introducing crop coefficient and leaf area index to enhance evapotranspiration simulations in hydrologic models

“…The CAT model structure and feasible parameter range is presented in Figure . The model has been applied to various watersheds for different applications (Birhanu, Kim, Jang, & Park, ; Choi, Jang, & Kim, ; Jang, Kim, Ahn, & Kim, ; Jang, Kim, & Kim, ; Lee & Cho, ; Miller et al, ). The main hydrological processes of the CAT model are presented in Figure , and a detailed documentation on the function is provided by Kim et al ().…”

Performance of rainfall–runoff models in reproducing hydrological extremes: a case of the River Malaba sub-catchment

“…com/ site/ conyu tha/ tools-to-downl oad (accessed: 10 February 2021). These models were selected because they (1) are freely available online and (2) were found to be robust for rainfall-runoff modelling under various climatic conditions as demonstrated in several recent studies [27,36,[65][66][67][68][69].…”

Impact of Groundwater Abstraction on Hydrological Responses during Extreme Drought Periods in the Boryeong Dam Catchment, Korea

“…Jang et al [29,30] assessed the long-term hydrological behavior of agricultural reservoirs in the Idong catchment and analyzed the impact of future climate change on the hydrological responses and runoff in the Gyeongan-Cheon River Basin. Birhanu et al [31] assessed the results of five hydrological models, including the CAT, applied in 10 catchments in Korea. Choi et al [32] analyzed a short-term CAT runoff simulation and carried out a sensitivity analysis of soil parameters using three infiltration methods.…”