| Project/Area Number |
13556036
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | National University Corporation Tokyo University of Agriculture and Technology |
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Principal Investigator |
NISHIMURA Taku Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Associate Professor, 大学院・共生科学技術研究部, 助教授 (40237730)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Makoto Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Professor, 大学院・共生科学技術研究部, 教授 (50015096)
WATANABE Hirozumi Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Research Associate, 大学院・共生科学技術研究部, 助手 (80323757)
SAKAI Kenshi Tokyo University of Agriculture and Technology, Institute of Symbiotic Science and Technology, Associate Professor, 大学院・共生科学技術研究部, 助教授 (40192083)
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| Project Period (FY) |
2001 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥11,900,000 (Direct Cost: ¥11,900,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2002: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥5,600,000 (Direct Cost: ¥5,600,000)
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| Keywords | Dry bulk density / Heterogeneity / Saturated Hydraulic conductivity / Tension infiltrometer / Scaling / Transport of chemical / Unsaturated hydraulic conductivity / ディスクパーミアメータ / 水分特性曲線 / マルチステップ法 / ディスクパーミアメーター / 非相似多孔体モデル / 誘電率水分計 |
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| Research Abstract |
Apply dielectric constant method to measure volumetric water content of soils to assess dry bulk density of the soil. Volumetric water content couple with either mass wetness or wet bulk density can produce dry bulk density. Trials with time domain reflectometry(TDR) probe and Amplitude domain reflectometry(ADR) probe gave good results. Estimated dry bulk density agreed well with the measured dry bulk density of disturbed soils. For non disturbed soils, accuracy was worse than that of the disturbed soil however accuracy was good enough for practical purpose. Relatively, dry bulk density estimated by using volumetric water content and wet bulk density was better than that by using the combination of volumetric water content and mass wetness. This was due to arithmetic process of data calculation. Most significant source of estimation error was heterogeneity of water content distribution along with sensing rod of water content sensors. Laboratory experiment showed that especially for ADR probe, uneven distribution of water content collapsed reliability of measurement of volumetric water content.
Scaling of saturated hydraulic conductivity by using dry bulk density was conducted. Estimated saturated hydraulic conductivity distribution had similar spatial structure with measured ones. This was evaluated by using semrvariogram.
Performance of tension infiltrometer as in-situ measurement device of soil hydraulic property was examined. There were several improvements in tension infiltrometer and this improved easiness and time for measurement. Result of tension infiltrometer well explained leaching phenomena in upland field than common methods such as saturated hydraulic conductivity and cylinder intake rate.
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