Hydrological simulation evaluation with WRF-Hydro in a large and highly complicated watershed: The Xijiang River basin

Abstract

Study region: Xijiang River, South China. Study focus: This paper discusses the application of WRF-Hydro, a distributed hydrological model, to a complicated watershed. The model performance on simulating streamflow, soil moisture, soil temperature and evapotranspiration is evaluated. Changes and characteristics of streamflow and related variables simulated by the model are analyzed. New hydrological insights for the region: In this study, thirteen sensitive parameters used in this model are tested in large and small watersheds of the basin. It is found that large basins are more sensitive to base flow parameters than small basins. The WRF default soil type dataset is replaced by the Beijing Normal University (BNU) soil type dataset that is more accurate. The model can simulate temporal changes of streamflow as well as temporary variabilities of hydrological variables. The model can be applied in small and large watersheds. The trend of streamflow in the basin is spatially uneven with an increasing trend in the upper part and a decreasing trend in the lower part. The changes in streamflow are partly related to precipitation and evapotranspiration trends. The trends of 30-day maximum/minimum streamflow are not significant, but the reversals demonstrate significant changes during 1980–2018. This study is expected to serve as a reference for the application of the model in this basin and model calibration over different sizes of study area.

Keywords

• WRF-Hydro
• Streamflow
• Application
• Soil moisture
• Evapotranspiration
• IHA