1993 Fiscal Year Final Research Report Summary
Studies on movements of water and heat in the unsaturated zone with evapotranspiration from the soil surface
| Project/Area Number |
03680212
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
自然地理学
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
KAIHOTSU Ichirow Fac.of Inte.Arts and Sci., Dep.of Natural Env.Sci., Assoc.Professor, 総合科学部, 助教授 (60160959)
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| Project Period (FY) |
1991 – 1993
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| Keywords | evapotranspiration / unsaturated zone / soil water / water balance / numerical experiment |
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| Research Abstract |
This study tried to make clear mechanisms of interactions between soil water movements and evapotranspiration from the sand soil surface covered with grass by carrying out field observations and numerical experiments. The obtained results are as follows :
1.Evapotranspiration from the soil surface depends on the conditions of grass development and soil wetness.
2.Thermal conductivity of the site soil depends on volumetric water content without roots.
3.Soil water movements after rainfall affects on thermal flux in the unsaturated zone.
4.During summer, vapor flux in the skin layr below the soil surface is relatively smaller than soil water flux calculated by the Richards equation.
5.The divergent zero flux plane of soil water play an important role in the unsaturated zone. It is produced as a result of the balance between groundwater recharge and evapotranspiration.
6.An physical model considered evapotranspiration from the grass surface for soil water movements is effective for simulation of the zero flux plane behaviors. However there is much room for further improvement (e.g., determination of soil moisture characteristics) for the quantitative simulation of soil water flux.
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