One-dimensional horizontal infiltration experiment for determining permeability coefficient of loamy sand |
| |
| Authors: | Shunjun HU |
| |
| Institution: | 1. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;2. University of Chinese Academy of Sciences, Beijing 100049, China;3. Central South Institute of Metallurgical Geology, Yichang 443003, China |
| |
| Abstract: | A knowledge of soil permeability is essential to evaluate hydrologic characteristics of soil, such as water storage and water movement, and soil permeability coefficient is an important parameter that reflects soil permeability. In order to confirm the acceptability of the one-dimensional horizontal infiltration method(one-D method) for simultaneously determining both the saturated and unsaturated permeability coefficients of loamy sand, we first measured the cumulative infiltration and the wetting front distance under various infiltration heads through a series of one-dimensional horizontal infiltration experiments, and then analyzed the relationships of the cumulative horizontal infiltration with the wetting front distance and the square root of infiltration time. We finally compared the permeability results from Gardner model based on the one-D method with the results from other two commonly-used methods(i.e., constant head method and van Genuchten model) to evaluate the acceptability and applicability of the one-D method. The results showed that there was a robust linear relationship between the cumulative horizontal infiltration and the wetting front distance, suggesting that it is more appropriate to take the soil moisture content after infiltration in the entire wetted zone as the average soil moisture content than as the saturated soil moisture content. The results also showed that there was a robust linear relationship between the cumulative horizontal infiltration and the square root of infiltration time, suggesting that the Philip infiltration formula can better reflect the characteristics of cumulative horizontal infiltration under different infiltration heads. The following two facts indicate that it is feasible to use the one-D method for simultaneously determining the saturated and unsaturated permeability coefficients of loamy sand. First, the saturated permeability coefficient(prescribed in the Gardner model) of loamy sand obtained from the one-D method well agreed with the value obtained from the constant head method. Second, the relationship of unsaturated permeability coefficient with soil water suction for loamy sand calculated using Gardner model based on the one-D method was nearly identical with the same relationship calculated using van Genuchten model. |
| |
| Keywords: | permeability coefficient one-dimensional horizontal infiltration cumulative horizontal infiltration wetting front distance Philip infiltration formula Gardner model |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《干旱区科学》浏览原始摘要信息 |
| 点击此处可从《干旱区科学》下载免费的PDF全文 |
|
