Author(s): Xiang Wenyan; Huang Jinhui
Linked Author(s):
Keywords: Design storm; Urban flooding; Theoretical frequency curve; I-D-F curve
Abstract: Due to the global changing climate，the hydrological cycle changed, hence impacting precipitation intensity, while the design storm is one of the most important criteria for retention/detention facilities and drainage systems, and could directly impact its security, so further study is essential. The paper took Tianjin City for an example, and used 52-year precipitation data to study the design storm. Two sampling methods were employed including annual maximum method and annual multisampling method. Four theoretical frequency distributions were employed including Gumbel Distribution, Generalized Extreme Value Distribution, ExponentialDistribution and P-Ⅲ Distribution, while the first two frequency methods were utilized for analysis of sample from annual maximum method and the latter two methods were utilized for analysis of sample from annual multisampling method. For the assessment of the goodness-of-fit for the results of theoretical frequency analysis, the coefficient of determination is utilized. Intensity-Duration-Frequency (I-D-F) curve was obtained from the theoretical frequency analysis, from which the design storm equations was obtained by Gauss-Newton Method and the standard deviation and relative standard deviation were used to assess the goodness of fit of the equations. The conclusion is that the annual multisampling method is better than annual maximum method, and that for the four theoretical frequency distributions, the P-Ⅲdistribution is most suitable in the city of Tianjin, so it is strongly recommended that the design storm can be revised through P-Ⅲ distribution under the joint efforts of scholars and the government to guarantee the demand of design purpose.
Year: 2013