摘要
崩岗是中国南方水土流失最严重的土壤侵蚀类型。文章通过对信宜市岗尾崩岗不同地貌部位的土壤物理性质和颗粒粒径组成的研究,探讨了崩岗不同地貌部位土壤物理性质与粒径变化规律,并揭示了崩岗侵蚀的发育机制。结果显示:(1)岗尾崩岗不同地貌部位土样中的含水率、容重、比重和孔隙度等物理性质存在明显分异,上部崩壁和崩积体土壤质地较为致密、紧实,经流水改造程度较弱;中下部沟道和冲积扇土样较为松散的土壤质地显示了流水作用参与程度较强。(2)颗粒粒径组成显示岗尾崩岗土样为含砾砂土,崩壁土样呈现了花岗岩风化壳未受侵蚀状态的原状土特征,崩坡上崩积体是重力作用和水力作用共同侵蚀的产物,而沟道和洪积扇则表现为以流水为主的沉积特征。(3)不均匀系数和曲率系数显示岗尾崩岗土体堆积时间较短,崩岗发育年龄较年轻,而崩岗地貌形态和植被覆盖状况也显示其正处于发育的阶段。
Collapsing hill is the most severe type of soil erosion in southern China.This study investigated the soil physical properties and particle size composition of different landforms in Gangwei Collapsing Hill,Xinyi City,and explored the changes in soil physical properties and particle size in different landforms,as well as reveals the development mechanism of collapse erosion.The results showed that:(1)There are significant differences in physical properties such as water content,bulk density,specific gravity,and porosity in soil samples from different landforms of Gangwei Collapse Hill.The soil texture of the upper collapsing wall and colluvial deposit is relatively dense and compact,and the degree of water transformation is relatively weak;the loose soil texture of soil samples from scour channel and alluvial fan indicates a strong participation of water flow.(2)The particle size composition shows that the soil sample of Gangwei collapse hill is gravel containing sandy soil.The soil samples from the collapsing wall exhibit the undisturbed soil characteristics of the weathered granite crust,while the soil samples from the colluvial deposit are the product of the combined erosion of gravity and hydraulic forces,while the soil samples from channel and alluvial fan exhibit sedimentary characteristics dominated by flowing water.(3)The uniformity coefficient and curvature coefficient indicate that the accumulation time of collapsed soil is relatively short.The development age of the collapsing hill is relatively young,and the geomorphic form and vegetation coverage of the collapsing hill also indicate that it is in the stage of development.
作者
黄日辉
李奕信
HUANG Rihui;LI Yixin(School of Geographical Sciences,Lingnan Normal University,Zhanjiang 504248,Guangdong,China;College of Earth Sciences,Chengdu University of Technology,Chengdu 610051,China)
出处
《华南地理学报》
2023年第3期92-100,共9页
South China Geographical Journal
基金
湛江市海洋青年人才项目(2021E05023)
岭南师范学院人才引进专项项目(1170918278)
关键词
崩岗
土壤物理性质
颗粒粒径
风化壳
collapsing hill
soil physical properties
particle size
weathered crust
