金沙江干热河谷元谋强侵蚀区土壤裂隙形成与侵蚀机制

Mechanism of Formation of Soil Crevice and Soil Erosion in Intensively-eroded Area in Yuanmou Dry and Hot Valley of Jinshajiang River

根据金沙江干热河谷元谋地区红土层非常发育的裂隙现象,对该地区典型区土壤裂隙形成的环境和土壤剖面进行了调查,并采样进行相关土壤理化性质测定、粘土矿物X-射线衍射分析以及土壤微形态研究。结果表明:(1)该区旱季丰富的土壤裂隙形成与该区主要分布的第四系古红土层(QS)和第四系元谋组的黄棕色土层(QY)等红土母质特性有密切关系;(2)由于土壤裂隙非常发育,成为了边坡崩塌和直接产生重力侵蚀的成因,加剧了土壤侵蚀过程,导致了土柱和土林等强侵蚀景观形成。研究表明,土壤裂隙是金沙江干热河谷元谋地区强烈侵蚀和水土流失所特有的成因。

The Yuanmou dry and hot valley of the Jinshajiang river is one of the fragmental environment areas in China, where the soil and water loss was very serious. It is difficult to interpret the peculiar soil erosion phenomenon using the traditional opinion. This study based on the observation in the environment and soil profiles which related with developed soil crevice, and using such means as chemical analysis, X - ray diffraction pattern and micromorphology. Results showed that： （1） In this area, the developed soil crevice was significant correlated with the parent material of the quaternary system old red horizon （Qs） and yellow brown horizon （Qy）. （2） The developed soil crevice was the main reason for soil fall and gravity erosion, as the result, the soil erosion increased obviously. Finally this paper advanced a new viewpoint that soil crevice was the most important reason of the seriously soil and water loss formation.