Basic Study on Evaluation Method Soil Moisture in Small-Scale Basin
| Project/Area Number |
13650559
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
水工水理学
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| Research Institution | Kitami Institute of Technology |
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Principal Investigator |
NAKAO Takashi Kitami Institute of Technology, Dept. of Civil Engineering, Research Assistant, 工学部, 助手 (60101523)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2002: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | pendular water / spherical particle model / suction / Moisture characteristic curve / Numerical Simulation / 土壌水分特性曲線 / 配位数 / 不飽和浸透流 / 流出解析 |
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| Research Abstract |
It is well known that the movement of water in a soil can be described by unsaturated flow equations. The relationship between suction and water content is needed to solve these equations, and this relation can be obtained through indoor experiments. The water retained in pores among particles with radii in the range of 10^<-3> mm to 1 mm can be regarded as comprising most of the free water. The free water forms a pendular ring between two particles under unsaturated conditions due to surface tension acting on the free water. The pendular ring depends on the geometrical configuration of two particles. In this paper, a conceptual model for evaluation of the suction and water retention volume among spheres with different radii is proposed from a microscopic viewpoint. The results of quantitative analysis using this model are presented. In order to calculate the suction and water retention volume in natural soil, the coordination number of a particle must be determined. Assuming that the particle size distribution and porosity are known, the average coordination number can be estimated.
The results of the proposed model agree well with the experimental results in the case of relatively low water content. However, as the proposed method focuses on only isolated pendular rings between two particles, it is impossible to extend our method to the higher water content region.
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Report
(3 results)
Research Products
(6 results)
