The mechanism of underground leakage of soil in karst rocky desertification areas—A case in Chenqi small watershed, Puding, Guizhou Province

The underground leakage of soil is a special type of soil and water erosion in karst rocky desertification areas. Based on a case study in the Chenqi small watershed — a serious karst rocky desertification area, the process and mechanism of underground leakage of soil is illustrated. The results show that special geologic and environmental conditions in the karst area provide favorable transport channel and accommodation space for underground leakage of soil. Substantial leakage of surface precipitation is the force f or soil leakage toward underground. The disintegration of the aggregate into the finer particles makes the soil leak easier to move along the soil pores and the rock fissures and goes down into underground. In conditions of the infiltrating and softening by the water, the soils that deposited in the karst fissures or caves become more plastic and are able t o creep along the soilrock interface and migrate to the underground river which leads to the leakage of the surface soil. This study is expected to provide a theoretical support for the soil and water conservation in karst rocky desertification areas.