首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2篇
  免费   0篇
地球物理   1篇
综合类   1篇
  2009年   1篇
  2006年   1篇
排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
Infiltration is the process of water penetrating into soil, generally referred to as the downward movement of water from the soil surface[1,2]. This process is af-fected by water supply and the soil infiltrability, de-termines the amounts of water entering into soil pro-file and the surface runoff. Infiltrability is defined as the infiltration flux of a unit area under atmospheric pressure and sufficient water supply. The actual infil-tration rate and/or the infiltrability is expressed in m/s …  相似文献   
2.
Soils in the Knersvlakte are particularly prone to crusting and have lower inherent infiltrability than other soils across western southern Africa. Micromorphological techniques were used to examine the structure and porosity of soil crusts in the Knersvlakte to ascertain why crusting is so intense in this region. Quantile regression using boundary lines was employed to examine the relationships between infiltrability and soil properties for all samples (n = 67). This analysis showed that infiltrability is potentially maximal at low water- dispersible 'clay plus silt' content and low silt content (r^2 = 0.72 and 0.64; respectively, n = 67) (Figure 2). The strength of crusts, pH, EC, clay mineralogy, and water-dispersible clay, silt and 'clay plus silt' content were compared, and a pore analysis using optical microscopy was undertaken on images of six soil thin sections (n = 6) (circular and parallel polarizers). Pore analysis was further undertaken on five horizontal slices of equal dimensions taken through each soil thin section. The porosity samples with low infiltrability (〈 100 mm·hr^-1, n = 4) had greater crust strength, lower porosity (both total and in the least porous slice) and greater water-dispersible 'day plus silt' and silt content than the porosity samples with high infiltrability (〉 100mm·hr^-1, n = 2). The porosity samples with low infiltrability showed a trend of lower pH and greater water dispersible clay percentage. Porosity varied within the porosity samples due to the presence of dense clay/silt bands (〈 0.5 mm in width) with relatively few air vesicles. The porosity samples with horizontal slices of low porosity (but large numbers of air vesicles) had low infiltrability, while those without slices of low porosity (and relatively few air vesicles) had high infiltrability. We conclude that the intense crusting and resultant low infiltrability of soils in the Knersvlakte appears to be related to the formation of thin, dense clay/silt bands in the pedoderm.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号