Intercomparison of ten ISI-MIP models in simulating discharges along the Lancang-Mekong River basin

He Chen; Junguo Liu; Ganquan Mao; Zifeng Wang; Zhenzhong Zeng; Aifang Chen; Kai Wang; Deliang Chen

doi:10.1016/j.scitotenv.2020.144494

Intercomparison of ten ISI-MIP models in simulating discharges along the Lancang-Mekong River basin

Sci Total Environ. 2021 Apr 15:765:144494. doi: 10.1016/j.scitotenv.2020.144494. Epub 2020 Dec 24.

Authors

He Chen¹, Junguo Liu², Ganquan Mao³, Zifeng Wang³, Zhenzhong Zeng³, Aifang Chen³, Kai Wang³, Deliang Chen⁴

Affiliations

¹ School of Environment, Harbin Institute of Technology, Harbin 150090, China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
² School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China. Electronic address: liujg@sustech.edu.cn.
³ School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
⁴ Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Gothenburg 40530, Sweden.

PMID: 33421770
DOI: 10.1016/j.scitotenv.2020.144494

Abstract

Water resources are of strategic importance for socioeconomic development. Many hydrological models (HMs) and land surface models (LSMs) have been developed for water resources assessment. However, systematic evaluation of discharge simulation from multiple models is still lacking in the Lancang-Mekong River basin. Here, we evaluated the performances of ten HMs and LSMs by evaluating their simulated discharge against observations at the basin scale. The selected models were within the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP2a) framework driven by Global Soil Wetness Project 3 (GSWP3) climate forcing data. Five discharge percentile series were used to evaluate the model performances for low, mean, and high flows. The intercomparison according to four statistical criteria revealed considerable differences exist in model performances for different discharge percentiles, indicating a large uncertainty caused by the choice of models with different degree of physical complexity and sensitivity to the quality of the input data. The models generally performed better for high flow than for low flow. Furthermore, the models generally performed better in downstream than in upstream, with the exception of close to the estuary, where complex processes involving interactions between freshwater and saline water are present. It is not surprising that the two calibrated model (WaterGAP2 and WAYS) are superior over the other models. This systematic intercomparison provides insights into the model behaviours and accuracies in discharges predicting with varying intensities, which can aid in quantifying uncertainties in water resources simulation at the basin scale.

Keywords: Hydrological models; ISI-MIP; Land surface models; Model evaluation.