太湖地区水稻土大孔隙的CT扫描分析与灰色关联评价  

CT Scan Analysis and Grey Relativity Evaluation of Macropores in Paddy Soils in Taihu Lake Region

作　　者：沃飞[1] 陈效民[1] 方堃[1] 吴华山[1] 

机构地区：[1]南京农业大学资源与环境科学学院

出　　处：《土壤》2008年第2期319-326,共8页Soils

基　　金：国家自然科学基金项目(40371055);高等学校博士学科点专项科研基金项目(20030307018)资助

摘　　要：利用CT扫描技术分析了太湖地区3种典型水稻土(白土、黄泥土和乌栅土)中大孔隙的孔隙度、大孔隙数量、孔隙平均面积和孔隙等效直径的变异系数在不同深度的分布情况及影响因素.结合灰色关联理论,定量地说明在不同深度下发生大孔隙优先流的难易程度及决定因素。结果表明:表层大孔隙优先流的形成能力最强,并随着深度加大呈波浪式下降趋势且变化平缓。在0～55 cm深度,黄泥土大孔隙优先流的形成能力最强,乌栅土其次,白土最弱:55 cm以下,无法明显区分出3种土壤这种能力的强弱。乌栅土地区地下水受到污染的潜在危险最大。大孔隙度和等效直径的变异系数对优先流的产生影响最大。Three typical paddy soils. （White soil, Huangni soil and Wushan soil） in the Taihu Lake Region were studied. The CT scan technology was used to analyze distribution and affecting factors of macroporosity, number, average area, equivalent aperture and their variation coefficients in different depths of the soils. With the aid of the grey relativity method, likelihood of occurrence of macropore preferential flow in different depths of soils and its decisive factors were quantitatively evaluated~ Results reveal that preferential flow was most likely to occur in the surface layer, and the likelihood declined with the depth, showing a gently wavy curve In soil layer from 0 to 55 cm in depth, preferential flow is most likely to occur in Huangni soil, which is followed by Wushan soil and white soil. But in the soil layer below the depth of 55 cm, it is difficult to differentiate the three soils in preferential flow. The potential risk of groundwater pollution is the highest in Wushan soil region than the other two regions because of its high groundwater table. The variation coefficients of macroporosity and equivalent aperture of macropores seem to be the most important factors affecting occurrence of preferential flow.

关 键 词：大孔隙 CT扫描 灰色关联评价 优先流 

分 类 号：S152.5[农业科学—土壤学] X825[农业科学—农业基础科学]