2017年绥德“7·26”暴雨重现期分析

Analysis of “July 26” Rainstorm Return Period of Suide Station in 2017

2017年绥德"7·26"暴雨历时短、强度高、雨滴大,洪水形成时间短、洪峰高、含沙量大。运用P-Ⅲ型概率分布函数、GEV概率分布函数和Gumbel概率分布函数对大理河绥德站过去58 a的降水数据进行拟合,发现3种概率分布函数均通过K-S检验和A-D检验,其中GEV概率分布函数拟合效果相对最优,Gumbel概率分布函数拟合效果最差。采用这3种函数对"7·26"暴雨的重现期进行了计算,出于防洪考虑以及从本次暴雨造成的灾情损失来看,本次暴雨重现期应为GEV概率分布函数估计的约200 a一遇。

In July 26th 2017, Suide County experienced an extraordinary rainstorm event. This rainstorm had some particularly features： theshort duration of development, the high intensity of rainfall and the big raindrop. Consequently, the rainstorm caused severe flooding, which had a short formation time, high peak flow and hyper-sediment concentration. P-Ⅲ, GEV and Gumbel probability distribution function had been used in this research to simulate the precipitation frequency by using the last 58 a data. K-S test and A-D test show that the annual maximum precipitation in Suide County is drawn from these 3 given probability distributions. Comparing with the empirical data, the GEV distribution simulates the probability of observation is the best while the Gumbel has the worst simulation. The return period of precipitation in July 26 has been calculated and the results suggest that it should be about 200 a when considering the flood control standard and the loss in this local rainstorm disaster.