Gaoyuan qixiang (Jun 2022)

Hydrological Utility of CLDAS-Prcp Multi-source Fusion Precipitation Products in Qijiang River Basin—Taking WRF-Hydro Model as an Example

  • Yun SU,
  • Chunxiang SHI,
  • Wenshu MAO,
  • Shuai SUN,
  • Bingqi XIE,
  • Danhua ZHAI

DOI
https://doi.org/10.7522/j.issn.1000-0534.2021.00073
Journal volume & issue
Vol. 41, no. 3
pp. 617 – 629

Abstract

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In order to evaluate the hydrological utility of CLDAS-Prcp multi-source fusion precipitation products and the simulation effect of WRF-Hydro model in small and medium-scale watersheds， Firstly CLDAS-Prcp and IMERG-Final multi-source fusion precipitation products are used to analyze the spatial distribution characteristics of cumulative precipitation and the time series change characteristics of hourly rainfall in seven typical flood cases in the Qijiang River basin， then the two products are respectively used to drive the WRF-Hydro models to simulate 7 typical flood cases in the Qijiang River basin.The outputs of the process are analyzed and compared with the measured flow.The results show that： （1） CLDAS-Prcp depicts more details than IMERG-Final in the spatial distribution of accumulated precipitation， and it is more accurate in terms of large-value drop areas and total precipitation； both precipitation products can well describe the change trend of the hourly surface rainfall in the basin during the flood period， and CLDAS-Prcp is closer to the observation data on the peak and the change trend of surface rainfall.（2） Based on the 4 runoff simulations of the CLDAS-Prcp multi-source fusion precipitation product， 3 runoff simulations have a Nash coefficient higher than 0.9， showing excellent performance； among the 4 runoff models based on the IMERG-Final multi-source fusion precipitation product， except for the 20200622 flood event， the Nash coefficients of the other simulations are all lower than 0.7， indicating that the parameter calibration and runoff simulation based on the CLDAS-Prcp fusion precipitation product are superior to the IMERG-Final fusion precipitation product.（3） The WRF-Hydro model is able to simulate the individual flood peak flow， which can accurately reproduces the time when the flood peak appears， and well describe the details of the flood process.In general， the CLDAS-Prcp multi-source fusion precipitation product and the WRF-Hydro model can be well applied in the hydrological simulation of small and medium-scale watersheds.

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