Location: Southwest Watershed Research CenterTitle: Intra-storm temporal patterns of rainfall in China using Huff curves
|YIN, S.Q. - Beijing Normal University|
|XIE, Y. - Beijing Normal University|
|GUO, W.L. - Beijing Normal University|
Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2016
Publication Date: 12/1/2016
Citation: Yin, S., Xie, Y., Nearing, M.A., Guo, W. 2016. Intra-storm temporal patterns of rainfall in China using Huff curves. Transactions of the ASABE. 59(6):1619-1632. https://doi.org/10.13031/trans.59.11010.
Interpretive Summary: The temporal patterns of precipitation within a storm event are important to hydrologic and soil erosion processes. The mathematical curves that describe temporal patterns of precipitation within a storm event are called hyetographs. A convenient and established method for characterizing precipitation hyetographs is with the use of Huff curves, which are basically mathematically normalized versions of the hyetograph. The reason that normalized curves are used is so that results found in one location or during one time of rainfall record can often more easily be extrapolated to other locations and other time periods. In this study, hyetographs from 11,801 erosive rainfall events with a time-resolution of one minute were collected over 30-40 years from 18 weather stations located across the central and eastern parts of China. Then the data were analyzed to produce Huff curves. Our results showed that nearly 40% of the events had peak rainfall intensities in the first quarter of the storm, with 65% having the peak intensity in the first half of the storm. These early peaking events also tended to be more intense and erosive. The erosivity index (power to cause soil erosion) was 71% greater, on average, for storms with the peak rainfall in the first quarter of the storm compare to the storms with peak intensity in the last quarter. The higher intensity events generally arise from convective thunderstorm processes in summer. Statistical testing showed that differences of Huff curves for the 18 stations, spreading across much of China, were minor. The Huff curves developed in this study shared similar distributional characteristics with those reported for Illinois in the USA, Malaysia, and the Santa Catarina of Brazil, which may lead to important techniques for characterizing temporal patterns of rainfall in many areas of the world.
Technical Abstract: The intra-storm temporal distributions of precipitation are important to infiltration, runoff and erosion processes and models. A convenient and established method for characterizing precipitation hyetographs is with the use of Huff curves. In this study, 11,801 erosive rainfall events with one-minute resolution data collected over 30-40 years from 18 weather stations, located across the central and eastern parts of China, were analyzed to produce Huff curves. Each event was classified according to the quartile period within the event that contained the greatest fraction of rainfall. The results showed that 38.3% of events had the maximum rainfall amounts in the first quartile, followed by the second (26.8%), the third (22.4%) and the fourth quartile (12.5%). Quartile I and Quartile II events were generally characteristic of shorter duration and heavier intensity events. Quartile I events averaged 24% shorter durations than Quartile IV events, whereas the mean intensity, Iave, the mean maximum 30-min intensity, I30, and the mean rainfall erosivity index, EI30, were 1.71, 1.22, 1.23 times greater than those for Quartile IV, respectively. The proportion of Quartile I events was less for events of longer duration, whereas the proportion of Quartile III and Quartile IV were greater. Events arising from convective processes in summer resulted in a greater percentage of Quartile I events. Kolmogorov-Smirnov tests showed that differences of Huff curves for 18 stations spread for 24 degrees of latitude, 30 degrees of longitude and 1870m of altitude were minor. Regional Huff curves developed in this study shared similar distributional characteristics with those reported for Illinois in the USA, Malaysia, and the Santa Catarina of Brazil, which may lead to an important conclusion that temporal characteristics of rainfall are similar across a very large part of the world.