1997 Fiscal Year Final Research Report Summary
A study of mapping evapotranspiration at a forested watershed using ballon remote sensing.
| Project/Area Number |
08456082
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | Ehime University |
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Principal Investigator |
EBISU Nobuhiro Ehime University, College of Agriculture, Assistant Professor, 農学部, 助手 (60176782)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAKITA Osamu Forestry & Forest Products Research Institute, Remote-Sensing Labo., Chief, 林業経営部, 研究室長
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| Project Period (FY) |
1996 – 1997
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| Keywords | Balloon / Remote sensing / Forested areas / Mapping of evapotranspiration / Surface temperature / Evapotranspiration / Infrared radiation thermometer |
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| Research Abstract |
The purpose of this study is to estimate the mapping of evapotrans piration at forested areas using Surface Temperature method (S.T.method) which is applied to estimate evapotranspiration using the image data of surface temperature by an infrared radiation thermometer and the energy balance data. The images of surface temperature are obtained using balloon remote sensing of about 100-200 meters height above the ground.
The results of this study are listed below :
1.The study area is located at Japanese cypress stands in Ehime University forest in 1996. A small balloon was equipped with an infrared radiation thermometer sensor, a control system, a battery and a micro wireless video camera. The measurement of surface temperature by this remote sensing system was carried out for each 15 seconds. The angle of sensor was controlled by an operator who checks the pictures sent through this system. There were obvious differences between the surface temperature of the stands measured from the balloon and from the ground. The evapotranspiration estimated from the balloon is smaller than from the ground. It is considered that surface temperature is more accurate using balloon remote sensing than using the infrared radiation thermometer on the ground.
2.The observation was carried out at two study areas of Japanese cypress stands in 1997. These stands were different in aspect and slope angle. The difference of surface temperature at the two plots was 1.8ﾟC on the average. Evapotranspiration using S.T.method at the plot where surface temperature was lower was about 0.28mm/4hr higher than the other plot and evapotranspiration using Bowen ratio method was showed similar values. The balloon remote sensing by S.T.method is a good method for estimating evapotarspiration at wide forested areas with different aspects and slope angles and requires measurement of air temperature, wind speed and net radiation at these plots.
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