Modified formula for estimating the Bowen ratio – description of the determination procedure

Abstract

Aim of the study: One way of estimating evapotranspiration is to use the heat balance structure of active surface. Material and methods: The paper shows how to derive a formula estimating the Bowen ratio by using measurement data of heat balance structure of various crops, and in the next step, apply that ratio to estimate evapotranspiration. A two-stage method is described, in which the first step is to determine empirical index W, and the second step is to calculate the Bowen ratio. This allows the researcher to see the results in a graphic format, while searching for the best outcome, and to implement simple tools offered in spreadsheets. Results and conclusions: The obtained formulas made it possible to estimate evapotranspiration of agricultural crops with high accuracy in relation to the measured value.

Keywords

• active surface heat balance components
• bowen ratio
• modelling