特大暴雨重现期不确定性对抽水蓄能电站暴雨频率计算成果的影响

Influence of the Uncertainty from Return Period of Extremely Heavy Rainstorm on the Frequency Analysis of Rainstorm of Pumped-storage Power Station

抽水蓄能电站暴雨频率计算中常遇到特大暴雨,特大暴雨重现期存在不确定性。为此,提出了特大暴雨重现期不确定性的确定方法,并研究了其对暴雨频率计算成果的影响。应用实例结果表明:假定的特大暴雨重现期越长,设计暴雨越小,且减小幅度逐渐降低,应加强对特大暴雨重现期的调查考证,尤其是在200 a内;设计暴雨中适线法成果最大,矩法次之,线性矩法最小,且适线法成果比矩法成果大10%~20%,故可采用适线法推求的设计暴雨成果作为抽水蓄能电站的采用值。

Extremely heavy rainstorm is often encountered in the frequency analysis of rainstorm of pumped-storage power station and the return period of extremely heavy rainstorm is uncertain.Therefore,a method to determine the uncertainty of the return period of extremely heavy rainstorm is proposed,and its influence on rainstorm frequency analysis is studied.The results indicate that,(a)the longer the assumed return period of extremely heavy rainstorm is,the smaller the design rainstorm will be,and the reduction rate will gradually decrease,so the investigation and research on the return period of extremely heavy rainstorm should be strengthened,especially within 200 years;and(b)the results of the curve-fiting method for the design rainstorm are the largest,followed by the moment method,and the linear moment method is the smallest,and the results of the curve-fitting method are 10%-20%larger than those of the moment method,so the design rainstorm results derived by the curve-fiting method can be used as the adopted value of pumped-storage power station.