3-3泥石流冻土.ppt

环境地质学Environmental Geology 主讲人：万新南教授 　　　　Prof. Wan xinnan 环境地质学 Environmental Geology * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology 6、Pre降水、江河与洪水7、Mass Wasting Processes　表层整体再塑 　　（滑坡、泥石流、溶蚀、塌陷） 8、海岸线与海岸塑造过程9、生态与植被 * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology 7、Mass Wasting Processes 　　　　　　　　表层整体再塑 　（滑坡、泥石流、溶蚀、塌陷） * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology Mass Wasting Processes There is nothing inorganic.... The earth is not a mere fragment of dead history, stratum upon stratum like the leaves of a book, to be studied by geologists and antiquaries古玩家 chiefly, but living poetry like the leaves of a tree, which precedes flowers and fruit-not a fossil earth, but a living earth.... Henry David Thoreau * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology Mass Wasting Processes A、Flowing sand, landslides, and rock falls are examples of mass wasting, the general term for gravitationally induced downslope movement of debris. B、Mass-wasting processes operate on sloping lands; eventually the debris reaches a stream or gully where fluvial processes continue the erosional process. * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology Mass Wasting Processes * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology Mass Wasting Processes Rockfall 　　Rockfall occurs where a cliff of bedrock is exposed to weathering and pieces of the bedrock are pried loose and fall, bounce, or roll to rest at the base of the cliff. The resulting deposit is called talus崩塌岩堆 (Behre, 1933; Schumm and Chorley, 1966; Rapp, 1976). In an irregularly eroded cliff, talus cones may develop in the gully冲沟 head areas (Fig.6.2). In more extensive cliffs, coalescing聚集 talus cones form a more continuous blanket of debris referred to as scree 山麓碎石(Jeffreys, 1932; Adrews, 1961). * Part three　　地球表层的塑造过程 环境地质学 Environmental Geology Mass Wasting Processes Rockfall 　　Talus will not rest at an angle greater than the angle of repose. The angl