Evapotranspiration is one of the important elements related water cycle and there is many kind of measurement method of evapotranspiration today. This study developed mini lysimeter for the purpose of direct measurement of evapotranspiration and installed on 5th, July, 2010 at the field of MRI which located at Tsukuba, Ibaraki, Japan for continuous measurement and understand relation between evapotranspiration and meteorological elements expecially radiation elements. And compared the evapotranspiration data of lysimeter with Bowen Ratio Method. The result of this study is as follows;
There is high related with solar radiation and evapotranspiration with R2=0.947. and 46 % of solar radiation converted into evapotranspiration during clear 5 days. In net radiation also highly related with evapotranspiration, we can derive evapotranspiration is mainly controlled by radiation energy in clear days.
From the 104 days data, there is only 9 % difference between Bowen Ratio Method and evapotranspiration of lysimeter which was developed from this study is very useful to estimate evapotranspiration at field site with simple and high accuracy.
High accuracy and resolution measurement of evapotranspiration by lysimeter can give a chance further study of meteorological phenomena of on ground expecially in night time condensation which means abnormal energy flow.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 라이시메타 제작과 관측
  2.2. 관측 장소 선정
  2.3. 기상 관측 자료와 라이시메타 관측 자료
 3. 결과 및 고찰
  3.1. 단파복사와 순복사의 관계
  3.2. 단파복사와 증발산
  3.3. 순복사와 증발산
  3.4. Bowen방법과 라이시메타 증발산
 4. 결 론
 참 고 문 헌

• 이부용(대구가톨릭대학교 환경과학과) | Bu-Yong Lee (Dept. of Environmental Science, Catholic University of Daegu) Corresponding Author
• Shigenori Haginoya(일본 기상연구소)