Research on Calculating Method for the Design Rainfall of Urban Flooding Prevention Engineering
Download as PDF
Chuanjun Tang, Te Hou, Zhipeng Liu, Rongjian Nie, Wei Cai and Bin Xiao
For the moment, on the one hand, the rainstorm intensity formula that applied in urban flooding prevention mostly comes from urban development department’s derived formula, which the longest duration is only 2 hour, it has been unable to meet the requirement of design rainfall, so a long duration rainstorm intensity formula is needed. On the other hand, for the prevention of urban flooding disaster more from the total amount of water and the flow hydrograph, so the rainfall duration distribution that can reflect the real situation of the Basin Rainfall is also needed. In view of the above problems, at first, the study integrated and normalize the original rainfall data that offered from meteorological data of a City, a total of 52 years rainfall data of the center city, and selected P- III frequency distribution curve to fit the sample data, then prioritized a group of parameters that the error from six classical methods is smallest, thus the long duration rainstorm intensity formula was obtained, chose a typical rainfall process from original rainfall, then adopted the typical duration amplification method, combined with the storm intensity formula to derive the rainfall duration distribution under the corresponding return period and lay a theoretical foundation for the design and planning for the urban rain water drainage system.
Design rainfall; urban flooding prevention; rainfall duration distribution; rain water drainage system