长江黄河含沙量垂线分布的分形研究

Fractal study on sediment concentration distributions in Yangtze River and Yellow River

为了从流体内部结构入手分析挟沙水流含沙量分布,以长江、黄河实测资料为例,从分形标度的角度出发,探讨了天然河道含沙量垂线分布的规律。研究结果表明:天然河道含沙量垂线分布呈二阶累计和变维分形现象,分维数可以反映含沙量垂线分布的均匀程度,分维数越大,含沙量垂线分布越均匀;长江含沙量垂线分布的分维数(绝对值)要小于黄河的分维数,并且同一条河道的不同位置分维数不同;含沙量垂线分布的分维数大小与泥沙粒径、水深等有关。

In order to analyze the sediment concentration distributions of the sediment-laden flow in terms of flow internal structure,the vertical distribution laws of sediment concentration in the natural rivers are explored from the perspective of fractal scale based on the measured data of the Yangtze River and Yellow River.The results show that the vertical distributions of sediment concentration in the natural rivers has a second-order accumulated variable-dimensional and fractal phenomenon,and the fractal dimension can reflect the uniformity of the sediment concentration distribution,the greater the dimension is,the more uniform the sediment concentration distribution is.The fractal dimension of vertical distribution of sediment concentration of Yangtze River is smaller than that of Yellow River,and the dimensions at different locations of the same river are different;the dimension sizes is related to the sediment particle diameter,water depth and so on.