Professor Huiling Yuan's group from the School of Atmospheric Sciences at Nanjing University has made new progress in hydrologic uncertainty analysis over the upper Huaihe river basin. The related paper, titled Using multiple satellite-gauge merged precipitation products ensemble for hydrologic uncertainty analysis over the Huaihe River basin, was published recently in Journal of Hydrology, a top hydrologic journal with an impact factor of 3.727 for 2017. Doctoral candidate Ruochen Sun was the first author, and Professor Huiling Yuan was the corresponding author. It was Yuan's group's third consecutive paper accepted by the Journal of Hydrology in recent years.
Satellite–gauge precipitation products combine the advantages of satellite rainfall estimates with rain gauge data, and have been widely used for hydrological applications. However, the inaccuracies of the precipitation products together with hydrologic model structure and parameter uncertainties, could cause great uncertainty in streamflow predictions, limiting the applicability and reliability of satellite–gauge precipitation products at the basin scale.
To address these existing hydrologic uncertainties, doctoral candidate Ruochen Sun carried out a series of researches on the upper Huaihe River basin under the supervision of Professor Yuan. To begin with, four of the latest satellite–gauge Quantitative Precipitation Estimate (QPE) products were statistically evaluated over the Huaihe River basin during 2003–2012 and applied into the distributed Variable Infiltration Capacity (VIC) model to assess hydrologic utilities. The results were reported in a paper titled Evaluation of the latest satellite–gauge precipitation products and their hydrologic applications over the Huaihe River basin, published in Journal of Hydrology in 2016. The paper has been cited 41times according to Google Scholar and was awarded 12th Annual Outstanding Academic Paper in Natural Science by the Nanjing Association for Science and Technology in 2018. In their second research, the group proposed a newly developed residual error model to address the complicated heteroscedasticity over Huaihe river basin, and results showed that the improved model produced more accurate streamflow predictions with the higher reliability. The related paper was published in Journal of Hydrology in 2017 and has been cited three times according to Google Scholar. The research was showcased by a printed poster in the Student Conference Poster Session during the 98th AMS annual meeting and won the First place poster presentation among student entries in the hydrological sector.
Based on the results of previous studies, the latest research considered the parameter uncertainty and model structural uncertainty and benchmarked the performances of various precipitation products on streamflow prediction. It investigated the influence of precipitation uncertainty on parameter uncertainty and streamflow prediction, and the individual streamflow simulations selected from each streamflow uncertainty interval were combined using Bayesian model averaging (BMA). The BMA results showed satisfying hydrological performance in terms of deterministic and probabilistic streamflow predictions, outperforming the outcomes of high-quality regional precipitation products. The study provided valuable guidance in the utilization of satellite–gauge precipitation products in ungauged basins.
These works were supported by the National Natural Science Foundation of China.
Links to the papers:
Sun, R., H. Yuan*, and Y. Yang, 2018. Using multiple satellite-gauge merged precipitation products ensemble for hydrologic uncertainty analysis over the Huaihe River basin. Journal of Hydrology. 566, 406-420. https://doi.org/10.1016/j.jhydrol.2018.09.024
Sun, R., H. Yuan*, X. Liu, and X. Jiang, 2017. Effect of heteroscedasticity treatment in residual error models on model calibration and prediction uncertainty estimation. Journal of Hydrology. 554, 680-692. https://doi.org/10.1016/j.jhydrol.2017.09.041
Sun, R., H. Yuan*, X. Liu, and X. Jiang, 2016. Evaluation of the latest satellite-gauge precipitation products and their hydrologic applications over the Huaihe River basin. Journal of Hydrology. 536, 302-319. https://doi.org/10.1016/j.jhydrol.2016.02.054