Abstract:

Based on precipitation data from 1981 to 2013 of Zibo in the middle area of Shandong Province, the temporal and spatial variations of precipitation were analyzed firstly. According to the annual maximum value sampling method, combined with P-Ⅲ distribution, exponential distribution and Gumbel distribution, the theoretical frequency of rainstorm intensity in main urban area of Zibo was simulated and analyzed, at the same time, the relationship curve of  return period, rainstorm intensity and rainfall duration was given, then on the basis of the least square method and Gauss-Newton method, the parameters of rainstorm intensity formula were calculated. Finally, using absolute error and relative error as the main evaluation indexes of the formula, the rainstorm intensity formula was obtained for the main urban area of Zibo. The results show that  rainstorm intensity in Zibo in recent 30 years showed an upward trend, and rising amplitude decreased from short duration to long duration. The average annual rainstorm days in the plain were more than that in the mountain areas.The single and general formulas obtained by P-Ⅲ distribution and the least square method were the best, and the average absolute standard deviation and relative standard deviation of total formula were 0.026 mm/min and 2.35%, respectively.The values of rainstorm intensity caculated by new formulas were more than those caculated by the old rainstorm intensity formulas worked out in the 1980s, and increasing amplitude increased with the return period. The revising rainstorm intensity formulas had good fitting effect on rainstorm intensity in adjacent plain areas.

Key words:  regularity, rainstorm intensity, distribution curve, parameters, formula

摘要：

利用鲁中淄博地区1981～2013年降水资料，分析降水变化的时空规律。基于年最大值法选样，采用P-Ⅲ型分布、指数分布和耿贝尔分布对淄博主城区暴雨强度进行理论频率拟合分析，得出重现期—暴雨强度—历时的关系曲线，结合最小二乘法和高斯—牛顿法推求暴雨强度公式参数，以绝对误差和相对误差作为公式主要评价指标，得出淄博主城区暴雨强度公式。结果表明：淄博市近30 a来暴雨强度呈上升趋势，上升幅度由短历时向长历时递减；年平均暴雨日数呈现山区多、平原少的空间分布，其中，淄博主城区最少为1.6 d，南部山区博山最多为2.5 d；P-Ⅲ型分布曲线拟合理论频率—最小二乘法推求参数得到的暴雨强度总公式和单一公式效果最好，总公式平均绝对标准差和平均相对标准差分别为0.026 mm/min和2.35%；新修正的暴雨公式计算的暴雨强度值多数比1980年代编制的大，偏大幅度随重现期的增加而增加，对临近平原地区暴雨强度有较好的拟合效果。

关键词: 变化规律, 暴雨强度, 分布曲线, 参数, 公式