| Project/Area Number |
09650575
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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 | Daido Institute of Technology |
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Principal Investigator |
SHIMOJIMA Eiichi Daido Institute of Technology, Civil Engineering Dept., Professor, 工学部, 教授 (80027276)
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| Co-Investigator(Kenkyū-buntansha) |
TAMAGAWA Ichiro Nagoya University, Institute for Hydrospheric-Atmospheric Sciences, Assistant Pr, 大気水圏科学研究所, 助手 (40273198)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1998: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | evaporation from bare-soil / salinization / arid and semi-arid areas / experiment / numerical simulation |
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| Research Abstract |
This research aims at clarifying the relation between evaporation from bare-soil surfaces and salinization in arid and semi-arid areas through an experiment and a numerical simulation. The following results were obtained.
(1) In the experiment, dune sand in Western China was used for setting up a sand column and a controlled atmospheric condition (temperature, humidity and radiation) was applied on the upper surface of the column with initially uniform water content profile (field capacity). 1) Liquid water, water vapor and solute dissolved from soil particle behaved in a manner of similarity, and evaporation rate varied inversely as square root of time. 2) Application of radiation suppressed evaporation through a downward transport of vapor. 3) High salinization occurred in a dried zone ahead of the drying front lead descent of its vapor density but increase in resistance to the vapor transport owing to the crystallization was not seen. 4) Under the periodic atmospheric condition simulating night-time (non-radiation and moist air) and daytime (radiation and dry air), periodic occurrence of evaporation-condensation near the sand surface played an important role in the evaporation process.
(2) A numerical simulation using a newly formed calculation-scheme for water and solute movement predicted characteristics of evaporation-salinization seen in the experiment, and its solutions became very useful information for understanding the evaporation-salinization process.
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