Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples
If soil hydraulic conductivity or water holding capacity could be measured with a small volume of samples, it would benefit international fields where researchers can only carry a limited amount of soils out of particular regions. We performed a pinhole multistep centrifuge outflow method on three t...
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MDPI AG
2021-04-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/13/9/1169 |
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| author | Long Thanh Bui Yasushi Mori |
| author_facet | Long Thanh Bui Yasushi Mori |
| author_sort | Long Thanh Bui |
| collection | DOAJ |
| description | If soil hydraulic conductivity or water holding capacity could be measured with a small volume of samples, it would benefit international fields where researchers can only carry a limited amount of soils out of particular regions. We performed a pinhole multistep centrifuge outflow method on three types of soil, which included granite decomposed soil (Masa soil), volcanic ash soil (Andisol soil), and alluvial clayey soil (paddy soil). The experiment was conducted using 2 mL and 15 mL centrifuge tubes in which pinholes were created on the top and bottom for air intrusion and outflow, respectively. Water content was measured at 5, 15, and 30 min after applying the centrifuge to examine the equilibrium time. The results showed that pinhole drainage worked well for outflow, and 15 or 30 min was sufficient to obtain data for each step. Compared with equilibrium data, the retention curve was successfully optimized. Although the curve shape was similar, unsaturated hydraulic conductivities deviated largely, which implied that <i>K<sub>s</sub></i> caused convergence issues. When <i>K<sub>s</sub></i> was set as a measured constant, the unsaturated hydraulic properties converged well and gave excellent results. This method can provide soil hydraulic properties of regions where soil sampling is limited and lacks soil data. |
| first_indexed | 2024-03-10T12:02:20Z |
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| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T12:02:20Z |
| publishDate | 2021-04-01 |
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| series | Water |
| spelling | doaj.art-e5eb488e76834c8d9c63a723124e35cc2023-11-21T16:53:40ZengMDPI AGWater2073-44412021-04-01139116910.3390/w13091169Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil SamplesLong Thanh Bui0Yasushi Mori1Graduate School of Environmental and Life Science, Okayama University, Okayama 700–8530, JapanGraduate School of Environmental and Life Science, Okayama University, Okayama 700–8530, JapanIf soil hydraulic conductivity or water holding capacity could be measured with a small volume of samples, it would benefit international fields where researchers can only carry a limited amount of soils out of particular regions. We performed a pinhole multistep centrifuge outflow method on three types of soil, which included granite decomposed soil (Masa soil), volcanic ash soil (Andisol soil), and alluvial clayey soil (paddy soil). The experiment was conducted using 2 mL and 15 mL centrifuge tubes in which pinholes were created on the top and bottom for air intrusion and outflow, respectively. Water content was measured at 5, 15, and 30 min after applying the centrifuge to examine the equilibrium time. The results showed that pinhole drainage worked well for outflow, and 15 or 30 min was sufficient to obtain data for each step. Compared with equilibrium data, the retention curve was successfully optimized. Although the curve shape was similar, unsaturated hydraulic conductivities deviated largely, which implied that <i>K<sub>s</sub></i> caused convergence issues. When <i>K<sub>s</sub></i> was set as a measured constant, the unsaturated hydraulic properties converged well and gave excellent results. This method can provide soil hydraulic properties of regions where soil sampling is limited and lacks soil data.https://www.mdpi.com/2073-4441/13/9/1169unsaturated hydraulic conductivityretention curvemultistep outflowcentrifuge methodHYDRUSinverse solution |
| spellingShingle | Long Thanh Bui Yasushi Mori Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples Water unsaturated hydraulic conductivity retention curve multistep outflow centrifuge method HYDRUS inverse solution |
| title | Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples |
| title_full | Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples |
| title_fullStr | Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples |
| title_full_unstemmed | Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples |
| title_short | Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples |
| title_sort | pinhole multistep centrifuge outflow method for estimating unsaturated hydraulic properties with small volume soil samples |
| topic | unsaturated hydraulic conductivity retention curve multistep outflow centrifuge method HYDRUS inverse solution |
| url | https://www.mdpi.com/2073-4441/13/9/1169 |
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