淮河流域洪涝变化的信息维研究

STUDY ON THE INFORMATIVE FRACTAL DIMENSION FOR THE FLOOD SERIES IN HUAIHE RIVER BASIN

以一定洪涝指标建立的淮河流域近五百年洪涝变化序列为基础，采用分形理论和方法，分析了淮河流域洪涝变化的分形结构特征；计算了淮河流域不同等级洪涝序列的信息分维及其随时间的变化。结果表明，淮河流域洪涝序列是一种极不规则的Ｃａｎｔｏｒ集合；信息分维与洪涝发生的频度呈反相关关系，即洪涝程度越重，信息分维值越低，所反映的气候层次相对越高。信息分维及其变化有望成为时间序列变化趋势和气候层次的诊断指标。

Based on the flood series in Huaihe River Basin for the last 500 year period(1470～1991) which established by a certain rule of flood grade,the fractal characteristics of flood series in Huaihe River Basin are analysed and the informative fractal dimension and its moving change are calculated according to the fractal theory in this paper.The analysis shows that the flood series in Huaihe River Basin is an unregular Cantor Set which is selfsimilar.The value of informative fractal dimension is inverse proportion to the flood frequency.The more severe the flood is,the lower the informative fractal dimension becomes and the higher the climatic level is.The informative fractal dimension and its moving change may become a practical analytical index for the change of flood series and the climatic levels.