标题：Estimation of Aman Rice Evapotranspiration Using Bowen Ratio Energy Balance Method and its Comparison with Some other Methods under Bangladesh Condition
摘要：The study was conducted in the field laboratory of the Environmental Science Department, Bangladesh Agricultural University, Mymensingh during Aman rice season of 2005 to estimate field evapotranspiration (ET0). The Bowen Ratio Energy Balance (BREB) method was used to estimate ET0. A comparison between ET0 and ET from pan evaporation (EPan) and with three other empirical methods (e.g., Penman (Ep), Priestley-Taylor (EPT) and Makkink (EMK) method) was also made to know whether ET0 is agreed to other methods or not under Bangladesh condition. ET0 varied with climatic conditions and growth stages of rice plant. It showed the highest value (7 mm d-1) when Rn (17.66 MJ m-2 d-1) and temperature (30 °C) reached its maximum values and relative humidity reached its minimum value (78%). ET0 was also positively related to wind speed i.e. it showed increasing trend when wind speed increased. Linear regression between ET0 and ET obtained from empirical methods and pan evaporation method indicated that the Ep and EPT presented the highest agreements with ET0 (correlation coefficient was 0.91with Ep; 0.91 with EPT and 0.89 with EMK and 0.74 with ETpan).
关键词：Evapotranspiration;Bowen Ratio Energy Balance Method;Pan Evaporation;Empirical Methods
