中国东部山地泥石流发育的第四纪环境背景及减灾对策

根据中国东部山地古泥石流沉积记录 ,推断在地形条件具备的前提下 ,泥石流形成经过了冰 (缘 )期气候作用下的物质积累和间冰 (缘 )期气候作用下的水动力作用过程 ,二者在时间上具有差异性。按照晚第四纪以来物质与水动力条件的空间波动范围 ,可将中国东部泥石流的形成划分为 3个区 ,北部主要受控于季风降水 ,中部主要受控于物质积累 ,而南部则只与地形切割等因素联系密切。据此提出相应的减灾对策。

THE QUATERNARY ENVIRONMENTAL BACKGROUND OF DEBRIS FLOW EVOLUTION IN EASTERN CHINA AND THE MEASUREMENT FOR HAZARDS MITIGATION

Based on the record of old debris flow deposits in Eastern China,the forming conditions of debris flow are studied .It is stated that the materials of debris flow accumulated mainly in glacial or periglacial stages when the physical weathering was strong,and the motive power of water for debris flow formed mainly in interglacial or interperiglacial stages when the precipitation increased rapydly.According to the limits of the space change of material conditons and water motive power conditions,the formation of debris flow can be devided into three patterns:In the north part of Chian,the forming is controled with monsoon precipitation.The forming is controled by materials accumulated in the medium part of China,and is connected with landform in the south part of China.On the basis of the three patterns,the measurment for reduce disaster is discussed.It is concluded as followed:1.The ation and evolution of debris flow is a result of the nautral environmental development in the Eastern China.2.The debris flow disaster is formed through the re_adjustment of the cold climate deposits under the conditions of the modern interglacial stage climate.3.In different pattern region,the limited conditions of debris flow is not indentical.So the measurement for reduce disaster in different region should be based on different conditions.It is important that the law of the fluctuation of the monsoon's end part be studied in the north part of the eastern China.The study on the deposits of old debris flow in the middle part and the landform condition in the south part of the Eastern China is the key work for reduce disaster.