关键词: 汛期分期; 集对分析法; 均值标准差法; 距平百分率法; 联系度; 分类标准; 阈值;

Abstract: In order to reveal influence degree of different classification methods on flood reason division by Set Pair Analysis, we adopted Set Pair Analysis and rationality testing methods to explore influence of common classification methods such as mean standard deviation method and anomaly percentage method on connection degree of Set Pair Analysis, based on Qiyi Reservoir in Xinjiang Basin of Jiangxi Province.Also, we explored optimal k-threshold of mean standard deviation method and optimal p-threshold of anomaly percentage method.The results showed that the optimal k-threshold of the mean standard deviation method was 0.56～0.58,and the optimal p-threshold of the anomaly percentage method was 0.42～0.44.The threshold value had an impact on symbol quantization and flood season division results through affecting the classification interval range.According to rationality test, the optimal division result of mean standard deviation method was the closest to that of the rationality test.However, the optimal division result of anomaly percentage method was different from that of rationality test.Therefore, the mean standard deviation method was more suitable for Set Pair Analysis.It is suggested that the selection of the optimal classification interval and the comparative analysis of the division results should be performed when the Set Pair Analysis is applied to the flood season division.

Key words: flood season division; Set Pair Analysis; mean standard deviation method; anomaly percentage method; connection degree; classification standard; threshold value;