Location: Southwest Watershed Research CenterTitle: Minimum inter-event times for rainfall in the Eastern region of China Author
|Wang, W. - Beijing Normal University|
|Yin, S. - Beijing Normal University|
|Xie, Y. - Beijing Normal University|
Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2018
Publication Date: 1/5/2019
Citation: Wang, W., Yin, S., Xie, Y., Nearing, M.A. 2019. Minimum inter-event times for rainfall in the Eastern region of China. Transactions of the ASABE. 62(1):9-18. https://doi.org/10.13031/trans.12878.
DOI: https://doi.org/10.13031/trans.12878 Interpretive Summary: The results of this study show that the time between rainfall events varies depending on the location. It is important for scientists to delineate between rainfall events in order to understand the statistics of rainfall properties. Our study also shows that these rainfall properties differ depending on how we define the minimum dry time between rainfalls that constitutes an independent rainfall event. Results of this study are consistent with results from other studies elsewhere in the world that have a similar climate, such as the United States and Australia. The results also show that we don’t need to have very detailed rainfall records of one-minute recorded data, but that one hour data is sufficient for calculating the inter-storm minimum event tines. The results will help scientists who want to study the characteristics of rainfall in different parts of the world and to model hydrologic and erosion processes.
Technical Abstract: Minimum inter-event time (MIT) is an index used to delineate independent storms from sub-daily rainfall records. An individual storm is defined as a period of rainfall with preceding and succeeding dry periods less than MIT. MIT is a critical parameter in storm property analysis and storm-based stochastic rainfall simulation. The exponential method was used to determine an appropriate MIT for the eastern and central parts of China based on observed one-minute resolution rainfall from 18 stations. Results showed that dry periods between storms greater than MIT followed an exponential distribution. MIT varied from a minimum of 7.6 at the Neijiiang station to 16.6 at the Fuzhou station, with an average for the 18 stations of 10.7 h. The average of values obtained using hourly data was 9.8 h. An average MIT of 10 h is suggested for eastern and central China. Ten years of records were necessary to obtain a stable MIT. Precipitation depth, duration, average intensity, and maximum 30-minute intensity were significantly related to MIT. Relative differences between mean storm properties with MITs of 2 h and 10 h were 45% for the precipitation depth, 84% for the duration, -20% for the rainfall intensity, and 27% for the maximum 30-min intensity. This indicates that more attention should be paid to the selection of the MIT index as it relates to storm properties.