基于Copula函数的设计暴雨雨型研究

Research on design rainstorm pattern based on Copula function

城市原有排水防涝系统设计标准偏低会导致洪涝灾害频率升高。设计暴雨雨型是制定排水防涝系统设计标准的重要依据和前提,对城市建设和洪涝治理至关重要。采用同频率法、SCS法、暴雨衰减指数法和概率密度函数(PDF)法对宿迁市设计暴雨雨型进行研究,基于Copula函数的风险联合概率模型对4种雨型结果进行对比分析。研究结果表明:同频率法和暴雨衰减指数法的设计雨型相似,风险率相近;SCS法的雨峰偏大,风险率较小,但其最大6 h时段的降雨不集中;PDF法的雨峰与同频率法一样,但其最大3和6 h雨量较为集中,风险率最小。本次的研究方法和结果可以对设计雨型的方法和对比提供新思路和参考。

Low design standards of urban original drainage waterlogging system would increase the frequency of flood disasters. Design storm pattern is an essential basis and prerequisite for formulating the design standards of drainage waterlogging prevention system and has large impact on urban construction and flood management. The same frequency method,SCS method,rainstorm attenuation index method and probability density function（ PDF） method have been used to obtain the design storm pattern of Suqian city. Based on the risk joint probability of Copula function,results of the four rain types have been analyzed. Results show that the same frequency method and rainstorm attenuation index method have the similar pattern and risk probability. The rain peak of SCS method is large and the risk probability is small,but the rainfall is less concentrated in the maximum 6 h period. Moreover,the PDF method has the similar rain peak with the same frequency method,while the maximum 3 h and 6 h rainfalls are relatively more concentrative,and the risk probability is the smallest. Results of this research could provide new ideas and references for the development and comparison of rain storm patterns.