利用统计估算放大法推求可能最大暴雨

Statistical estimate magnification method for deducing probable maximum precipitation

由于中国对赫氏法有不同的看法,因此在引进该法后,需要对该方法加以修正和改进,倾向于以离均系数Φm取代统计估算法中的Km值.统计估算法仅从实际发生的大暴雨中寻求Φmm,而没有放大的概念,所以利用该方法计算的PMP值往往偏小.统计估算放大法是通过水汽放大,对统计估算方法进行改进.应用统计估算放大法推算宁德地区PMP,计算结果表明,该方法较其他方法更合理.

The statistical estimate method based on actual rainfall data for calculating the statistical value Km has been widely applied to estimation of the probable maximum precipitation （PMP）. Because of different views on this method in China, it has been revised and refined by many researchers since it was brought in, and the statistical value Km was apt to be replaced by standardized variate Фm. The statistical estimate method seeks for Фmm only from actual rainfall without magnification; therefore, the estimated result of PMP based on this method is a little small. This study was conducted to improve the statistical estimate method by introducing a vapor magnification factor, and the improved method was applied to deduce PMP for Ningde City. The result shows that the method is reasonable.