摘要
土壤的地下漏失是喀斯特石漠化地区一种特殊的水土流失方式。本文以喀斯特石漠化严重地区——贵州普定县陈旗小流域为例,阐明了土壤地下漏失的过程及其机理。研究结果表明喀斯特地区特殊的地质环境为土壤的地下漏失创造了有利的空间条件;地表降水的大量渗漏为土壤的地下漏失提供了侵蚀的水动力条件;风干的土壤团聚体遇水易崩解,离散出的细粒物质可沿土间孔隙和岩溶裂隙向地下空间迁移;岩溶洞隙内填积的粘土在流水的浸润软化下呈可塑、软塑甚至流塑状,可向其下的溶洞、地下河蠕滑搬运,最终导致地表土壤漏失。
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 for 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 to 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.
出处
《中国岩溶》
CAS
CSCD
2010年第2期121-127,共7页
Carsologica Sinica
基金
国家重点基础研究发展计划(973计划)“西南喀斯特山地石漠化与适应性生态系统调控子课题‘西南喀斯特山地土壤侵蚀过程与水土流失危险度评价’”(No.2006CB403203)
上海市重点学科(地质工程)建设项目(编号:B308)
关键词
喀斯特石漠化地区
土壤地下漏失
团聚体
蠕滑迁移
karst rocky desertification area
soil underground leakage
aggregate
creep and migrate
