粘土矿物的环境意义以及对土渗透性的影响——以贵州普定为例

喀斯特地区的水文地质条件是生态环境保护和水土保持的物质基础。笔者等针对贵州典型喀斯特地区的第四系覆盖层进行相关水文地质研究,在普定陈旗堡村南的山坳坡地上,选择典型地质剖面,通过现场水文地质试验、室内渗透试验、物理性质试验以及矿物成分分析,测定土体的物理性质、矿物成分和渗透性,研究了喀斯特地区表层土体粘土矿物的环境指示意义。研究结果表明,喀斯特地区土体渗透系数受土体结构、粒度成分、矿物成分以及植物根系影响。同时土体中的蒙脱石遇水膨胀减弱了粘性土的粘聚力,并导致土粒易被冲蚀,不利于水土的保持,这也说明生态植被的保护和恢复对于水土保持非常重要。

Environmental Significance of Clay Minerals and Its Influence to the Soil Permeability--A Case Study of Puding County, Guizhou Province

The hydrogeology condition in karst area is the geological foundation of ecological environment, as well as the foundation of water and soil protection. Therefore, the author had studied on the hydrogeology to the Quaternary overburden in the typical karst area of Guizhou province. Geological sections were dug on the Valley and slope land in the south of Chenqibao village in Puding country. By means of several kinds of test, including in situ and laboratory tests, the physical properties, mineral composition and permeability of soil were measured. Based on the test results, the environmental signification of clay minerals had been analyzed in the surface soil . The results showed that permeability of soil in karst area was effected by the soil structure, grain size composition, mineral composition and plant root. Especially, because of the expansion of the montmorillonite and the late of soil formation age,. the cohesion of soil was weakened, the soil mass is easily eroded, it is baleful to soil and water conservation. The measures using ecological vegetation protect soil and hold water were needed.