摘要
混沌－分形研究是非线性地貌发育理论，尤其是非线性流水地貌学研究的前沿问题，是当代地貌学深层次研究的一个重要界面，在国内外刚刚起步。本文在概述国内外研究进展基础上，以黄河下游及长江中下游为例，运用粗视化方法，对不同河段、不同河型的河床深泓纵剖面进行了分维量计和检验。初步分析表明，冲积河流的河道纵剖面具有分维特征，可用来刻划河流纵剖面发育的复杂程度，结合河床起伏度的统计对比分析，可将其作为河流纵向消能的另一种量度。河流纵剖面的分维具有时空变化，其微小变化可以体现河型在时空上的分异和偏离。分维数值与某些环境因素及水力条件有关，如分维数值Ｄ与河床纵坡降Ｊ呈负相关。因此，可作为河型演变分析依据的佐证，预测河流纵剖面的发育趋势。
Nonlinearchaosfractal study is a forward problem of nonlinear geomorphological theory, especially for fluvial geomorphology, and also is one of important boundary faces in intensive investigation on geomorphology. This kind of studies is just beginning at home and abroad. In this paper, based on the review of the studies on fractal in geomorphology, the fractal of different reaches and the river pattern on longitudinal profiles in the Lower Yellow R. and the Middle and Lower Changjiang River has been measured and tested. A preliminary study shows that, obviously, these is a fractal property in the longitudinal profile for alluvial river channels. Fractal value of channel longitudinal profile changes with time and space. A small vibration of fractal for longitudinal profile is able to cause difference and divergence in river pattern. It is related to envirenmental factors and hydraulic conditions, e.g. there exists a negative regression between fractal and gradient in the rever channel, which can be regarded as an evidence in analysing the evolution of river pattern and with which the development of longitudinal profile can be prospected.
出处
《地理学报》
EI
CSSCI
CSCD
北大核心
1997年第2期154-162,共9页
Acta Geographica Sinica
基金
国家自然科学基金
