A Rahman, Md. Mazibur creator Jensen, Jens Raunso Chairperson Nielsen, Jens Moller Examination Committee Rahman, Md. Ataur Examination Committee DAAD, FRG Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1986 continuing eng 80 p. The study was conducted at the Asian Institute of technology, Bangkok, Thailand in 1986. Two lysimeters of size 1mx1m with the mariotte system designed according to TOMAR & O'TOOLE (1980) was used to measure evapotranspiration, while evaporation & transpiration was measured using a thin (1mm) transparent PVC tray on the lysimeter. Net radiation and reflected radiation was measured above the crop. All other climatic parameters were available from the agrometeorological station situated at the site. The full cover albedo of rice at 14 °04' North and 100° 44' East in Thailand using exponential relationship was 0.22, that of water surface as 0.08 , and the extinction coefficient for albedo as 0.618. The combination model was used to develop model for evaporation and transpiration with the inclusion of estimated correction factor in the wind function of PENMAN (1954, as cited in PENMAN, 1956) for evaporation from water surface, and on the wind function of STIGTER (1980) for transpiration from the canopy. For the period of LAI < 3. 0 a linear relationship varying from 0 to 0. 75 for transpiration, 1 to 0.32 for evaporation were used on the basis of LAI to calculate the correction terms in both the wind functions. And for LAI ~ 3.0 both the correction terms were estimated to be constant; 0.32 for evaporation and 0.75 for transpiration. The estimated E was within 1mm of E observed during the initial period, thought to be associated with the error in measurement of evaporation while the evaporation in the later period could be estimated within 0.2mm of accuracy. Estimated T was higher In the initial period by 1mm on average and later within 0.5mm. Finally ET could be estimated within o.5mm accuracy on average. A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Eng.) - Asian Institute of Technology, 1986 Plants Transpiration Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B19568 http://203.159.5.9/ait-thesis/detail.php?q=B19568 110910 20260818155452.0