Rainstorm magnitude likely regulates event water fraction and its transit time in mesoscale mountainous catchments: Implication for modelling parameterization

Jun Yi Lee, Yu Ting Shih, Chiao Ying Lan, Tsung Yu Lee, Tsung Ren Peng, Cheing Tung Lee, Jr Chuan Huang*

*此作品的通信作者

研究成果: 雜誌貢獻期刊論文同行評審

摘要

Event water transit time estimation has rarely been done for violent rainstorms (e.g., typhoons) in steep and fractured mountainous catchments where the range of transit time, potential controlling factors, and the validity of time-invariant parametrization are unclear. Characterized by steep landscape and torrential typhoon rainfall, Taiwan provides great opportunities for inquiring into the above questions. In this study, the hydrometrics and δ18O in rainwater and streamwater were sampled with a ~3-h interval for six typhoon events in two mesoscale catchments. The TRANSEP (transfer function hydrograph separation) model and global sensitivity analysis were applied for estimating mean transit time (MTTew) and fraction (Few) of event water and identifying the chronosequent parameter sensitivity. Results showed that the MTTew and Few varied from 2.0 to 11.0 h and from 0.2 to 0.8, respectively. Our MTTew in the mesoscale catchments is comparable with that in microscale catchments, showing a fast rainfall-runoff transfer in our steep catchments. The average rainfall intensity is a predominant indicator, which negatively affects the MTTew and positively affects the Few, likely activating preferential flow-paths and quickly transferring event water to the stream. Sensitivity analysis among inter-and intra-events demonstrates that parameter sensitivity is event-dependent and time-variant. A quick and massive subsurface flow without distinct mixing with groundwater would be triggered during large rainstorms, suggesting that time-variant parameterization should be particularly considered when estimating the MTTew in steep and fractured catchments at rainstorm scale.

原文英語
文章編號1169
期刊Water (Switzerland)
12
發行號4
DOIs
出版狀態已發佈 - 2020 四月 1

ASJC Scopus subject areas

  • 生物化學
  • 地理、規劃與發展
  • 海洋科學
  • 水科學與技術

指紋

深入研究「Rainstorm magnitude likely regulates event water fraction and its transit time in mesoscale mountainous catchments: Implication for modelling parameterization」主題。共同形成了獨特的指紋。

引用此