磨西河流域泥石流流域形态的非线性特征

泥石流是磨西河流域地质环境演化的一个重要地表过程,研究该流域内泥石流的地貌发育及演化特征可为磨西河流域第四纪以来地质环境的演变提供重要信息。通过对流域51条泥石流沟地貌形态的统计分析发现,磨西河流域内泥石流的分布在空间上表现出明显的不均性,流域内泥石流沟的数量与对应的主沟长度、主沟纵比降及流域面积之间存在着明显的分形现象,具有较高的自相似性。结果表明,泥石流沟谷形态的非线性演化特征及现象是对磨西河流域冰川环境和地质构造环境响应的直接结果,主要体现在现代冰川对流域的强烈侵蚀和贡嘎山隆升而导致流域的强烈下切。研究结果可为流域内泥石流灾害的形成机理、防灾减灾及流域环境演化提供理论依据。

NONLINEAR CHARACTERS OF DEBRIS FLOW EVOLUTION IN MOXI RIVER BASIN

Debris flow is an important earth surface process to the geologic environment evolution in Mo-xi river basin.Investigation of the formation and evolution of the debris flow stream can provide useful basic data for the research of geologic environment evolution in Mo-xi river basin since the Quaternary.Based on the topographical statistic data of 51 debris flow gullies,the distribution of debris flows in Moxi river basin shows an asymmetric character obviously.There are fractal phenomenon and self-similarity among the debris flow numbers and the channel length,channel gradient and catchments area.Finally,this paper discusses the debris flow nonlinear evolution character and its response to the environment.This result can provide basic data for debris flow hazard prevention and risk control in Moxi river basin.