中文摘要：

在模糊集合分析理论及一般方法的基础上，充分考虑汛期的发展变化具有的模糊性、随机性和过程性，以及降雨径流响应过程的特征，以汛期正向累计雨量序列及反向累计雨量序列为基础，重新构造出一新的累计雨量序列，并作为汛期划分研究的基本研究对象，提出了出入汛最高标准（ASMAX）的概念以及消除出入汛标准影响的处理方法。最后对于桥水库控制区域汛期的分期规律进行了实际应用研究，研究结果表明：于桥水库控制流域汛期开始于6月11日，结束于9月18日，其中主汛期开始于7月21日，结束于8月4日。这基本符合海河流域主汛期在“七下八上”的统计规律。也表明累计雨量序列在一定程度上可以反应出汛期所具有的过程性，更适合汛期的分期分析。

英文摘要：

Based on theory and general application method of fuzzy set analysis, fuzziness, randomness, processiveness of hydrology phenomenon and responding character of rainfall and runoff in flood seasons were considered in order to establish a serious of new accumulative rainfalls according to positive accumulative rainfall series and negative accumulative rainfall series. The series was used in stage division of flood season. This paper proposed the concept of highest thresholds of in and out flood season （ASMAX） to eliminate the impact of different thresholds. The concept and method were applied to clarify the stage of flood season in Yuqiao Reservoir watershed. It is identified that the flood season of this watershed should be between June 11 and September 18 and main flood period between July 21 and August 4. This conclusion is in accordance with statistic regulation of ＂July bottom and August top＂ ,which means that the main flood season of Haihe watershed is between the last ten days of September and the first ten days of August. Accumulative rainfall series uncover processing character of flood season to certain extent, so it is suitable in stage division of flood season.