中国泥石流形成,发展,分布与自然环境演变间的关系

根据泥石流发育条件的形成规律与自然环境演变规律之间的关系分析,泥石流物质来源主要积累于物理风化盛行的冰期或冰缘气候环境阶段,水动力条件主要出现在融冰雪水或降水骤增时间——即间冰期或间冰缘期(阶)气候环境阶段.庐山、北京西山和燕山都反映出这种规律性,以马兰期黄土层为标志,晚更新世晚期至少有2期泥石流堆积,全新世有4期泥石沉堆积.从而划分出泥石流发育的活跃期和停滞期,目前中国泥石流仍处活跃期,即相当于间冰期阶段.按中国泥石流发育条件形成与自然环境演变规律间的关系,中国泥石流发育系统有3种结构模式,即西部高山型,北方冰缘型,南方霜冻型.再按气候差异,绘出了中国泥石沉分区图.

RELATIONSHIP BETWEEN CHANGE OF NATURAL ENVIRONMENT AND FORMATION,DEVELOPMENT AND DISTRIBUTION OF DEBRIS FLOW IN CHINA

The materials of debris flow accumulated mainly in glacial or periglacial stages when the physical weathering was strong while the motive power of water for debris flow to form formed mainly in interglacial or interperiglacial stages when the precipita- tion and melted ice and snow increased repidly,according to the relationship between the laws of the formation of develop condition of debris flow and the change of natural envi- ronment.This is well shown in Lushan Mountain,West Mountains of Beijing and Yanshan Mountains.Being decided by the Malan Stage Loess,there were two stages of debris flow deposits in late Neopleistoceae and four in Holocene.Thus it can be devided into vigrous stages and stagnate stages of debris flow.China is now still in a vigorous stage, which correspond to interglacial or interperiglacial stage.According to the relationship between the laws of the formation of develop condition of debris flow in China and the change of natural environment,the formation system of the debris flow in China can be decided into three patterns:1) West Mountain pattern,2) North periglacial pattern and 3) South frostpattern.According furthermore to the difference of climate,the distribution map of debris flow in China is drawn.