亚热带山区泥石流的形成过程

THE FORMATIVE PROCESSES OF DEBRIS FLOW IN THE SUBTROPIC MOUNTAINOUS REGION OF CHINA

本文应用地貌学、水文学等方法进行了泥石流源地分类,阐述了各类源地泥石流形成过程,分析了各类源地的地貌演变对泥石流形成过程的影响。

China has vast subtropical areas of about 2 million km2, situated in the basins of The Yangtze River and The Pearl River, including the Yunan-Kwei-chow Plateau, the Hengduan Mountains, South-Eastern part of Qinghai-Xi-zang Plateau and Taiwan Mountain There are major areas where debris flow are distrobuted and impluened by human actionsThe debris flow occurring in subtropic mountainous region in China is mainly induced by rainfall. The supply sources in this region can be divided into two types, slope source (including falls, landslided, sheet flow) and channel source (rill, gully, ravine, canyon). Two kinds of debris flow, ear-thmechanical and hydrocal debris flow, usually occurred in the supplying types. These two types of debris flow can be converted from each other with the change of the relative content of soil and water from the supplying sources.When the amount of water contained in debris flow exceeds 23 of the total discharge, debris flow will be transformed into sediment-laden water.The control installations of debris flow source in subtropic mountainous region should be set in supply sources and suit them to different local condition (source type) , stages (process), and needs of society, while the installations in transportation-deposition area, the erosion and deposition power of vari.ous debris flow, particularly that of the fluid digging out channel, should be considered.Only by doing so can make the most of the installations.