1999 Fiscal Year Final Research Report Summary
Effect of the Thermal Environment of Dam Lakes and Their Surroundings on the Surface Vegital Cover
| Project/Area Number |
09660261
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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 |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Kochi University |
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Principal Investigator |
KAMII Yasunori Kochi University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (90169615)
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| Co-Investigator(Kenkyū-buntansha) |
CHIKAMORI Kunihide Professor Emeritus of Kochi University, 名誉教授 (10036717)
OUE Hiroki Ehime University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80213627)
FUKUSHIMA Tadao Ehime University, Faculty of Agriculture, Professor, 農学部, 教授 (90036319)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Evaporation / Evapotranspiration / Lake Surface Evaporation / Convection / Thermometer / Sensible Heat Transfer / Infrared Thermometer |
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| Research Abstract |
KAMII and CHIKAMORI investigated the water temperature of Nagase and Kagami Dam Lakes in , Kochi Prefecture from 1997 to 1999 by watching the water surface temperature using a infrared thermometer. They found smaller convection cells with the diameter of 10 - 20 cm, observed during October to December, continued to remain for 20 seconds or so. while the larger cells with the diameter of more than 0.5 m, observed in December, remained for thirty minutes or so. They calculated the velocity and discharge per unit area of vertical sinking flows at every 0.5 m depth by employing Vertical one dimension convection model developed by KIMURA et al.. According to it, the vertical velocities varied between 0.06 m/s to 0.1 1 6 m/s, while the discharge per unit area varied between 0.00016 mィイD13ィエD1/s/mィイD12ィエD1 to 0.015 mィイD13ィエD1/s/mィイD12ィエD1 in November and December, 1998. They also created convection cells in a small tank with I O cm diameter by artificial heating and natural cooling in the laboratory. They found the, convection cells are of sausage shape and bursted after a while.
FUKUSHIMA and OUE developed multilayer model to express the heat balance and radiation balance on the soil surface, then determined the parameters and confirmed the validity of the model by the data gotten in the experiment farm of Ehime University. In 1998 and 1999, they conducted the paddy field micro-meteorological conditions including heat transfer, vegital cover, water surface temperature, air temperature, vertical distribution of humidity, wind speed, and calculated the heat transfer coefficient between water surface and air. Moreover, they calculated air temperature, humidity, global radiation, wind speed by employing the multilayer model. The model showed good agreement with the actual data. They also observed water quality at a reservoir and a stream. and confirmed that there is some mechanism to leave nutritive salts in the reservoir.
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