On the Intensity Formula for Hard Rain in Central Districts of Zhaoqing
In this paper,the sample of precipitation for the central districts of Zhaoqing was identified using the method of annual maximum,and three probability functions,namely,the Pearson type Ⅲ distribu-tion,the Gumble distribution and the exponential distribution,were used to run fitting tests.The results are shown as follows.The accuracy of both the Pearson type Ⅲ and Gumble distributions passed the KS test,and the accuracy of hard rain intensity following the Gumble distribution was superior over that of the Pearson type Ⅲ distribution,which was eventually credited as the formula for hard rain intensity.It was then used to determine the intensity for hard rains that would recur in single periods.The findings are presented as fol-lows.The recurrence period for 1-h rainfall of 50 mm is within two years,which suggests an annual event,that of 24-h rainfall at the intensity level of hard rain is also within two years,which also suggests an annual occurrence,and that of rainfall at the level of exceptionally hard rain is more than 50 years.In coping with extreme rains that occur once in a hundred years or more,responses and managements have to be perfected.When intense rains are expected to be around,timely dispatches should be made of urban drainage pipes,regulation and storage ponds,and drainage channels.
climatologyhard rain intensitycurve of probability distributionrecurrence periodZha-oqing
万方数据
维普
