| Project/Area Number |
05402058
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Shimane University |
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Principal Investigator |
FUKUSAKURA Shigekazu Shimane Univ.Agriculture Professor, 農学部, 教授 (00032631)
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| Co-Investigator(Kenkyū-buntansha) |
KIHARA Yasutaka Shimane Univ.Agriculture Research Associate, 農学部, 助手 (30204960)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1993: ¥12,400,000 (Direct Cost: ¥12,400,000)
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| Keywords | simultaneous transfer / constant evaporation rate / falling evaporation rate / salt accumulation / water potential / heat of vaporization / 砂漠化 / 空隙層 / 蒸発 / 水分・塩分・熱の連成輸送 |
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| Research Abstract |
An experimental study of simultaneous transfer of water, salt and heat in soils during evaporation is discussed. Many laboratory experiments were performed with controlled temperature and humidity conditions in column of Tottori dune sand. These experiments indicated clearly that salt concentration of soil solution influenced behavior of evaporation rate.
In pure soil water, evaporation was characterized by three stages ; (1) the first constant evaporation rate stage in which soil water evaporated at soil surface, (2) falling evaporation rate stage in which evaporation surface moved from soil surface to soil, (3) the second constant evaporation rate stage in which soil water evaporated in soil. Thus, the behavior of evaporation rate was determined by depth at which soil water evaporated. Vapor transfer in soil pores was less than evaporation from soil surface.
On the other hand, evaporation rate decreased gradually in salty soil water. The constant evaporation rate didn't happened. The behavior of evaporation was only the falling evaporation rate stage. This reason is why soil water potential was decreased in salty soil solution..
In this study, it was clarify that evaporation phenomenon was simultaneous transfer in essential, we had to consider water, salt and heat transfer in interrelationship.
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