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选择广东粤北连南两个典型岩溶山地剖面,调查了剖面裂隙、漏斗等的垂直分布特征,采样分析了土壤粒度垂向变化。结果表明:碳酸盐岩的构造运动、差异风化和溶蚀等形成的裂隙、漏斗和孔穴在降水入渗、土壤自重力和溶蚀作用下成为土壤地下迁移的通道;漏斗、裂隙及孔穴主要分布在0-10 m的范围,根据横断面调查计算,漏斗土壤占整个断面面积的23.1%-28.1%,裂隙土占整个断面面积的5.3%-8.9%,孔穴土占0.16%,土壤面积占整个剖面面积的28.4%-37.16%。在漏斗和裂隙中土壤颗粒物以粗粉沙和砂粒为主,次为粘粒和细粉沙,随深度增加砂粒含量降低,粘粒含量总体呈增加趋势但其变化与漏斗和裂隙底部形态、角度、宽度等有关;土壤粒度分布特征证明岩溶山地土壤存在水平和垂直两个运移过程以及地表侵蚀、土壤细粒物质下渗和土壤细粒物质堆积三个迁移阶段。
Two typical karst mountain sections in southern Liannan of Guangdong Province were selected to investigate the vertical distribution characteristics of the fractures and funnels in the section and to analyze the vertical variation of the grain size. The results show that the fractures, funnels and cavities formed by carbonate tectonic movement, differential weathering and erosion are the channels of underground soil migration under the influence of rainfall infiltration, soil self-gravity and dissolution. The funnels, fractures and cavities are mainly distributed in the 0-10 m. According to the cross-sectional survey, the funnel soil accounts for 23.1% -28.1% of the total cross-sectional area. The fissure soil accounts for 5.3% -8.9% of the total cross-sectional area and the cave soil accounts for 0.16%. The soil area accounts for the entire section Area of 28.4% -37.16%. In the funnels and fissures, the soil particles mainly consist of coarse silt and sand, the next is clay and fine silt, with the increase of the depth, the content of sand decreases, while the clay content increases generally. However, , Width and so on. The characteristics of soil particle size distribution prove that there are two horizontal and vertical migration processes in karst mountainous soil and three migration stages of surface erosion, infiltration of soil granular material and accumulation of soil granular material.