NEGATIVE EFFECT OF DEPTH ON SATURATED HYDRAULIC CONDUCTIVITY OF HISTOSOLS
NEGATIVE EFFECT OF DEPTH ON SATURATED HYDRAULIC CONDUCTIVITY OF HISTOSOLS
复制标题
深度对组织溶胶饱和水力传导性的负面影响
DOI：
10.1097/00010694-198512000-00010
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
M. Lévesqué
中科院分区：
文献类型：
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作者：
S. P. Mathur;M. Lévesqué
我们检验了当前的概念，即深层有机土壤具有较低的饱和水力导率（Ksat），因为它们更腐殖化，并且这种退化和富含腐殖的层偏离了达西行为，因此Ksat随时间和驱动力而变化。使用8个标准，测量了8个原始泥炭地0 ~ 125 cm深度的所有可视层，并对其分解程度或腐殖化程度进行了表征。采用螺旋孔法测量0 ~ 60 cm、0 ~ 100 cm和0 ~ 125 cm深度层的Ksat。统计分析表明，Ksat随土壤厚度的增加而急剧下降，但腐殖化程度和分解程度随土壤厚度的增加变化不显著。因此，新确定的是，即使分解程度没有显著增加，Ksat也会随深度而降低。有人提出，当一个充满空气的空腔被创造出来进行Ksat测量时，产生并存在于有机土壤较低深度的甲烷受到压力、浓度、温度和密度梯度的影响。由于贾明效应，演化出来的气泡会堵塞一些孔隙空间。这一解释与我们的观察结果一致，并解决了文献中报道的其他异常现象。
We examined the current concept that deeper layers of organic soils have lower saturated hydraulic conductivities (Ksat) because they are more humified, and that such degraded and humus-rich layers deviate from Darcian behavior so that Ksat changes with both time and driving force. All visually discernible layers in 0− to 125-cm depths of eight virgin peatlands were measured and characterized for their degree of decomposition or extent of humification, using eight criteria. The auger hole method was used to measure Ksat of the 0− to 60-, 0− to 100-, and 0− to 125-cm depth layers. Statistical analyses revealed that Ksat decreased sharply as thickness of the soil increased, although the degree of decomposition or extent of humification did not change significantly with the soil thickness. It was thus newly established that Ksat decreases with depth even without a significant increase in the degree of decomposition. It was proposed that the methane, produced and present at lower depths of organic soils, was subjected to pressure, concentration, temperature, and density gradients when an air-filled cavity was created to make the Ksat measurements. The evolved gas bubbles would have blocked some pore spaces due to the Jamin effect. This proposed explanation is in accord with our observations, and it resolves other anomalies reported in the literature.