摘要
崩岗侵蚀是华南水土流失区最严重的一种土壤侵蚀类型。崩岗由崩壁、崩积堆和洪（冲）积扇３部分组成，其侵蚀过程包括崩壁的崩塌后退、崩积堆的再侵蚀及沟床侵蚀。当把花岗岩风化土体当作均质体看待时，因崩壁失稳而发生的片状崩落，其临界高度干燥时理论上可达８～９ｍ，而饱和状态时则下降到２～３ｍ；风化土体中节理、裂隙等软弱结构面的存在，致使崩壁往往发生滑塌和倾倒，崩壁失稳的临界高度同样降至２～３ｍ。崩积堆的再侵蚀主要是雨滴溅蚀和细沟侵蚀。当侵蚀基面下降时，沟床下切严重并危及崩壁和崩积堆的稳定。
Avalanching Erosion is one of the most severe
patterns of soil erosion in soil and water loss regions in southern China.Avalanching hill is
composed of three main parts, avalanching wall, pile and diluvial deposit. The major
avalanching erosion processes are backward collapse, re scouring of pile and ditch bed
erosion. Supposing the weathered granite pile is uniformly composed, the theoretically critical
height of collapse in plate form from avalanching wall losing stability can reach 8 to 9 meters in
dry soil condition, and 2 to 3 meters in saturated condition. The soft structure faces such as
joint and crack etc.in weathered pile often lead to slide and collapse with critical height of
avalanching wall of 2 to 3 meters. Splash erosion by raindrops and rill erosion are the major
forms of avalanching pile re scouring. The stability of avalanching pile and wall will be
seriously influenced by ditch bed scouring down when erosion base is lowered.
出处
《中国水土保持》
1999年第4期10-12,共3页
Soil and Water Conservation in China
关键词
崩岗侵蚀
地貌侵蚀
临界高度
水土流失
土壤侵蚀
avalanching erosion geomorphology system critical height southern China
