渔子溪流域泥石流沟谷演变的分形特征

Fractal Characters of Debris Flow Evolution in Yuzixi River Basin

泥石流作为渔子溪流域的一种重要地貌地质演变过程,研究该流域内泥石流沟谷地貌及演变过程对渔子溪流域的S303线灾后恢复重建工作提供科学的依据。通过对流域内的29条沟谷型泥石流各自的地貌形态特征统计分析,渔子溪流域内泥石流的发育分布在空间上呈明显的分形特征,泥石流沟发育数量与流域面积、主沟长度、主沟纵比降、流域相对高差以及流域形态系数存在明显的分形现象,分维值分别为0.577、0.92、1.192、1.412、0.978,具有较多的自相似性。研究结果表明:区域内泥石流沟谷形态演变的非线性特征主要为对区域内强烈地质构造活动响应的直接结果,主要体现为构造活动下地壳的迅速抬升沟谷的强烈下切。其研究成果可为该流域泥石流发生机理、防灾减灾工作提供理论依据。

Debris flow is an important geomorphologic evolution in Yuzixi river basin. Study on the formation and evolution of the debris flow can provide useful basic data for post-disaster restoration and reconstruction work in $303 of Yuzixi area. Based on the topography morphology statistics of 29 debris flow gullies, the distribution of debris flow shows a fractal characteristics in Yuzixi river basin. There is obvious fractal phenomenon and self-similarity a- mong the amount and the drainage area, channel length, channel longitudinal gradient, relative altitude and form fac- tor. The Fractal values of dimension were 0. 577, 0.92, 1. 192, 1. 412, 0. 978. Finally,this paper discusses the nonlinear evolution character of debris flow and its response to the intense geological tectonic activity, expressed in rise of earth eurst and valley downcut. The result can provides a theoretical basis for the mechanism for debris flow and the work of disaster prevention and mitigation.