长江上游河道剖面分维数与通航水力要素的关系

Relationship between the Yangtze River channel profile fractal dimension and navigable hydraulic elements

通过对向家坝坝下宜宾—朱沱河段建立一维及二维非恒定-分形数学模型,研究该河段及局部滩段水流条件,利用累计和变维分形方法,得到河道纵剖面河流长度分形维数和河道横剖面河流宽度分形维数。在此基础上,探讨了河道纵剖面分维数和河道横剖面分维数与通航水力指标的响应关系。研究结果表明:1)在宜宾—朱沱河段中,随着河道纵剖面分维数的减小,横剖面分维数逐渐变小。2)在满足最低通航流量要求情况下,宜宾—泸州段的纵剖面分维数的取值范围为-1.297^-1.049,泸州—朱沱段的纵剖面分维数的取值范围为-1.305^-1.032。3)在宜宾—朱沱河段中,某一流量下横剖面分维数值反映的是某断面的地形与该级流量的相关度,而滩段横剖面分维数反映的是全河段地形与流量过程的相关度。

Based on the one-dimensional and two-dimensional unsteady-fractal mathematical model of Yibin to Zhutuo reach downstream Xiangjiaba dam, we research the flow conditions and local beaches with the cumulative and variable dimension fractal method and obtain the channel length of fiver profile fractal dimension and fraetal dimension fiver cross-section width.We also probe into the response of the fiver profile fractal dimension and fiver channel transverse section to the fractal dimension of navigation hydraulic indices.The results show that： 1） in Yibin -Zhutuo river reach, with the decrease of the longitudinal profile fractal dimension, the river cross-section fractal dimension turns smaller gradually; 2） under the condition of meeting the requirements of the lowest navigable flow, the profile fractal dimension values of Yibin - Luzhou section is within the range of - 1. 297 - - 1. 049, and that of Luzhou-Zhutuo section is within the range of-1. 305--1. 032; 3） in Yibin-Zhutuo fiver, under a certain flow cross- section, the fractal dimension numerical reflects the degree of correlation of the terrain and traffic, while beach profile fractal dimension reflects degree of correlation of the whole river topography and discharge process.