基于主成分分析法与量变质变判别模式的汛期分期

摘要

现行的汛期分期方法存在理论依据薄弱、考虑因素单一、阈值选取主观性强以及计算繁琐等缺陷,不能简便合理地进行汛期分期.为此,以李仙江流域为例,应用量变质变判别模式,结合主成分分析法,研究了基于综合指标、洪水指标以及暴雨指标的流域汛期分期规律,并与其他方法进行比较.结果表明,分期结果能反映指标的物理意义;汛期分期结果与分期指标有密切关系,在实际应用,应综合考虑多种指标;依据对立差异度意义划分的汛期过渡期具有较高的可靠性.%Current flood season division method often has many defects of weak theoretic basis,single factor,subjective threshold selection and complicated calculation,so it is difficult to make the stage of flood season easily and reasonably.Taking Lixianjiang Basin as an example,the flood season staging is studied by using the quantitative change and qualitative change discriminant mode theory and principal component analysis method based on rainstorm index,flood index and comprehensive index.The flood season staging results are compared with the results of other methods.The comparison shows that,(a) the flood season staging results can reflect the physical meaning of indexes;(b) in order to make the staging results more objectively in practical application,a variety of indicators must be taken into account comprehensively;and (c) the flood season division has higher reliability according to the meaning of difference degree.