摘要
以不同浓度的Ca(NO3)2电解质溶液为水源,在大雨强高坡度下进行降雨模拟,研究紫色土水土迁移特征,试图探索在较强的物理破坏下电解质作用对土壤侵蚀的影响。结果表明:自来水降雨对土壤中的电解质产生很强的稀释效应,改变土壤表面电场而产生强大的化学分散力(水合斥力和静电排斥力),因而产生土壤强烈的分散。降雨中加入的Ca(NO3)2电解质屏蔽了土壤电场而减弱了这种化学分散力,因而减弱了土壤分散,增加了渗透,减缓了水土流失的进程,这种作用随着降雨中Ca(NO3)2浓度的增高而增强。因此土壤侵蚀的根本原因是土壤电解质及其浓度控制下的化学分散力。
In order to explore the influence of the soil chemical dispersion force controlled by electrolytes on soil erosion under the strong physical disruption, the runoff water and sediment dynamic process in purple soils were studied with simulated rainfall experiments under different Ca（NOa）2 concentrations on 25~ runoff pan. Results showed that the dilution effects of soil electrolyte generated strongly due to the running water rainfall, bringing in the change of the soil surface electric field and therefore the strong chemical dispersion forces（hydration repulsion and electrostatic repulsion）. As a result, the dispersion of the soil could be observed obviously. With the addition of Ca（NO3）2 in the rainfall, the soil electric field was screened, and the chemical dispersion forces were weakened correspondingly. Thus, the dispersion of the soil were weaken, the infiltration increased, and the process of soil and water loss slowed down. These effects increased with the increasing of the electrolyte concentration in rainfall. The nature of soil erosion might be the chemical dispersion force under the control of the electrolyte concentration in the soil.
出处
《水土保持学报》
CSCD
北大核心
2013年第4期44-48,共5页
Journal of Soil and Water Conservation
基金
西南大学资源环境学院大学生科技创新"光炯"培育项目(20110208)
关键词
模拟降雨
土壤侵蚀
土壤化学分散力
紫色土
simulated rainfall
soil erosion
soil chemical dispersion force
purple soil
