崩岗侵蚀区土壤物理性质分层差异及其对崩岗发育的影响

Stratified Difference of Soil Physical Properties of Collapse Mound Erosion Areas and Its Influence to the Development of Collapse Mound

崩岗是我国南方红壤区最严重的土壤侵蚀类型之一。采集赣州市典型的花岗岩和红砂岩崩岗地区土壤样品,测试分析其红土层和母质层的黏聚力、内摩擦角和液塑性指标,结果表明:花岗岩崩岗地区母质层的抗剪强度显著低于红土层,而两者的液塑性指标值没有显著差异,说明母质层抗剪强度低是导致花岗岩地区崩岗发育的诱因;红砂岩地区红土层抗剪强度稍高于母质层,但两者间没有显著性差异,而红土层土壤液塑性指标值要显著高于母质层,说明母质层的低液塑性有利于红砂岩地区崩岗侵蚀的发育。花岗岩和红砂岩崩岗地区红土层的破坏容易诱发崩岗,因此保护红土层是预防崩岗侵蚀的关键。

Collapse mound is one of the most serious soil erosion types of red soil region in south of China. The paper collected soil samples from collapse mound erosion areas of granite and red sandstone in Ganzhou City,tested and analyzed the indexes of cohesive force,angle of internal friction and liquid plasticity of red soil layer and parent material layer. The outcomes show that a) the shearing resistance of parent material layer in collapse mound area is obviously lower than that of red soil layer and the indexes of liquid plasticity of the two are not remarkably different,showing the low shearing resistance of parent material layer is the inducement of collapse mound development of the area and; b)the shearing resistance of red soil layer in red sandstone area is slightly higher than that of the parent material layer,but there is no obvious difference between the two and the index of liquid plasticity of red soil layer is remarkably higher than that of the parent material layer,showing the low liquid plasticity of parent material layer is favorable to the development of collapse mound of red sandstone area. The damage of red soil layer in collapse mound soil erosion of granite and red sandstone will easily induce collapse mound. Thus,the protection of red soil layer is the key to prevent collapse mound erosion.