An objective method for partitioning the entire flood season into multiple sub-seasons

Information on flood seasonality is required in many practical applications, such as seasonal frequency analysis and reservoir operation. Several statistical methods for identifying flood seasonality have been widely used, such as directional method (DS) and relative frequency (RF) method. However, using these methods, flood seasons are identified subjectively by visually assessing the temporal distribution of flood occurrences. In this study, a new method is proposed to identify flood seasonality and partition the entire flood season into multiple sub-seasons objectively. A statistical experiment was carried out to evaluate the performance of the proposed method. Results demonstrated that the proposed method performed satisfactorily. Then the proposed approach was applied to the Geheyan and Baishan Reservoirs, China, having different flood regimes. It is shown that the proposed method performs extremely well for the observed data, and is more objective than the traditional methods. (C) 2015 Elsevier B.V. All rights reserved.