根据隔河岩水库防洪任务，采用变点分析方法对隔河岩水库汛期进行了分期研究与探讨。并将变点分析方法与成因分析方法、数理统计分析方法、模糊分析方法等计算结果进行比较论证。首先分析清江流域的洪水季节性规律，得出了其主汛期为6月上旬至7月下旬；进一步分析枝城洪水，得出了枝城洪水基本发生在6月20日以后；再通过清江、长江洪水遭遇时间特征分析，发现两江洪水遭遇主要发生在6月下旬至7月下旬。基于隔河岩水库的主要任务是为荆江河段防洪错峰，可将隔河岩水库的主汛期后挪20 d，得到水库汛期分期方式：汛前期为5月1日至6月20日；主汛期为6月21日至7月31日；汛末期为8月1日至9月30日。这为充分利用洪水资源提供了依据与基础。

The segmentation of flood season of Geheyan reservoir was researched by using the changing-point method. The calculated results obtained from this method are compared with those obtained by climatological analysis method, the statistic method of flood events and the fuzzy analysis method, respectively. Compared with the flood peaks in Jingjiang River section, the main flood season of Geheyan reservoir should be lagged by 20 days. So the flood season of Geheyan reservoir may be divided into three sub-seasons, i.e., the early flood season from May 1 to June 20, the main flood season from June 21 to July 31, and the late flood season from August 1 to September 30.