A dual-porous, inverse model of water retention to study biological and hydrological interactions in soil
A dual-porous, inverse model of water retention to study biological and hydrological interactions in soil
复制标题
用于研究土壤中生物和水文相互作用的双孔保水逆模型
DOI：
10.1111/ejss.12055
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发表时间：
2013
影响因子：
4.2
通讯作者：
Laudone G
中科院分区：
文献类型：
--
作者：
Laudone G
土壤生物水文过程的确定性建模需要一个明确的双孔孔隙结构模型，包含完全且单独表征的大孔隙度和微孔隙度。它还应包含与微孔相对于大孔的定位相关的信息。 这种过程的一个例子是一氧化二氮的生产，其中微孔“热点”中的细菌通过大孔途径获得营养物和气体。 我们提出了一种满足这两个标准的精密孔隙结构模型，即显式大孔隙率和微孔隙率及其位置关系。 为了演示模型的构建，我们描述了对单一土壤的建模，即来自英国贝德福德郡洛桑研究中心沃本实验农场的 Warren 土壤，尽管该建模方法适用于广泛的土壤和其他双多孔固体。 该模型能够拟合土壤的几个基本特性，即保水性、骨料尺寸分布以及微孔和大孔区域的孔隙率。 它包括树枝状临界渗透路径，微孔区域聚集在该路径周围。 对于与沃伦样本具有相同密度和质地的土壤，双多孔网络的饱和导水率具有正确的数量级。最后，我们证明了最终结构中的优先流动路径与临界渗流路径有何不同，并且只有 4.6% 的未堵塞大孔隙体积有助于流体流过该结构。
The deterministic modelling of bio‐hydrological processes in soil requires a void structure model that is explicitly dual‐porous containing fully and separately characterized macroporosity and microporosity. It should also contain information that relates the positioning of microporosity relative to macroporosity. An example of such a process is the production of nitrous oxide, in which bacteria in microporous ‘hot‐spots’ are supplied with nutrients and gases through a macroporous pathway. We present a precision void‐structure model that satisfies these two criteria, namely explicit macroporosity and microporosity, and their positional relationship. To demonstrate the construction of the model, we describe the modelling of a single soil, namely Warren soil from Rothamsted Research's Woburn Experimental Farm in Bedfordshire, UK, although the modelling approach is applicable to a wide range of soils and other dual porous solids. The model is capable of fitting several fundamental properties of soil, namely water retention, aggregate size distribution, and porosity of the microporous and macroporous zones. It comprises a dendritic critical percolation path, around which are clustered the microporous regions. The saturated hydraulic conductivity of the dual‐porous network is of the correct order of magnitude for a soil of the same density and texture as the Warren sample. Finally, we demonstrate how the preferential flow pathway in the resulting structure differs from the critical percolation pathway, and that only 4.6% by volume of the unclogged macroporosity contributes to the fluid flow through the structure.