暴雨资料的选样与统计方法

Sampling and statistics of Stormy Data

暴雨资料的选样有年最大值法和非年最大值法。在理论上，非年最大值法更适合城市排水。但目前所用的年多个样法需要很多资料，统计也很麻烦，以改用年超大值法为宜。年最大值法也可在城市排水中应用，但必须作重现期转换。提出了一种修正的年最大值法，在统计中先转换经验重现期，再推求暴雨公式。这样获得的暴雨公式与现行方法的结果基本一致。

Abstract There are two ways namely annual maximum (AMM) and non annual maximum (NAM) methods for stormy data sampling. Theoretically the later is more suitable to the urban discharge design. Recently the most used annual multi sampling method which demands too much data and complicate statistics will be replaced by annual overmaximal method as best. Also AMM could be applied for urban discharge design, but the conversion of recurrence will be done. The author proposes a modified AMM method, by which the empirical recurrence period will be converse first before the storm formula is deduced. The obtained storm formula by modified statistics is very similar to that by the currently used method. The frequency distribution in the statistics needs no any change.