IN SITU, ON-SITE AND LABORATORY MEASUREMENTS OF SOIL AIR PERMEABILITY: BOUNDARY CONDITIONS AND MEASUREMENT SCALE
IN SITU, ON-SITE AND LABORATORY MEASUREMENTS OF SOIL AIR PERMEABILITY: BOUNDARY CONDITIONS AND MEASUREMENT SCALE
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DOI：
10.1097/00010694-200102000-00003
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发表时间：
2001-02
期刊：
影响因子：
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通讯作者：
B. V. Iversen;P. Schjønning;T. Poulsen;P. Møldrup
中科院分区：
文献类型：
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作者：
B. V. Iversen;P. Schjønning;T. Poulsen;P. Møldrup
土壤透气性的测量是一种快速简便的方法，可以以不同的方式用于表征土壤。空气渗透率的建造，以测量空气渗透率（ka）在现场，现场（挖掘土壤样品），并在实验室中广泛的丹麦农业土壤。使用了两种不同尺寸的样品环（100 cm3和3140 cm3）。该装置最初在实验室中重新包装的土壤样品进行测试，以评估ka对样品大小的依赖性。结果表明，一致的ka值为两个样本量，表明只有很小的规模效应。在现场，空气渗透率进行了测量，在现场和现场使用大样品环。在假定各向同性土壤条件的同时，考虑到环下端的边界条件，通过使用“形状因子”确定原位透气性。使用Liang等人（1995）开发的形状因子表达式。两种测量方法的结果进行了比较，表明可靠的空气渗透率值使用梁等人的表达式。研究的土壤。在结构化土壤中的空气渗透率测量使用挖出的样品的不同大小表明，小样本一般产生较低的值和较高的变异性ka比大样本，根据一个有代表性的基本体积的概念。
The measurement of soil air permeability is a fast and easy method that can be used in different ways to characterize the soil. An air permeameter was constructed in order to measure air permeability (ka) in situ, on-site (exhumed soil samples), and in the laboratory on a wide range of Danish agricultural soils. Two different sizes of sample rings were used (100 cm3 and 3140 cm3). The device was initially tested in the laboratory on repacked soil samples to evaluate dependency of ka on sample size. The results showed consistent values of ka for both sample sizes, indicating only little scale effect. In the field, air permeability was measured in situ and on-site using large sample rings. Air permeability in situ was determined by using a "shape factor" taking into account boundary conditions at the lower end of the ring while assuming isotropic soil conditions. An expression for the shape factor developed by Liang et al. (1995) was used. The results from the two measurement methods compared well, indicating reliable air permeability values using the expression of Liang et al. for the soils studied. Air permeability in structured soil measured using exhumed samples of different size showed that small samples generally yielded lower values and higher variability in ka than large samples, in accordance with the concept of a representative elementary volume.