The Abtew Method is a

remote sensing Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...

method for measuring

evapotranspiration Evapotranspiration (ET) refers to the combined processes which move water from the Earth's surface (open water and ice surfaces, bare soil and vegetation) into the Atmosphere of Earth, atmosphere. It covers both water evaporation (movement of w ...

created by Wossenu Abtew in 1996. It is sometimes referred to as the radiative Abtew model.

Equation

The Abtew Method has advantages over other methods in that it only depends on solar radiation data. This is useful when modeling evaporation in areas where satellite remote sensing solar radiation data is the only data available. The equation is represented as

ET = K\frac

where *

ET

is evapotranspiration in millimeters/day *

K

is a dimensionless coefficient *

R_

is solar radiation measured in MJ/m^2/day *

\lambda

latent heat of vaporization In thermodynamics, the enthalpy of vaporization (symbol ), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy (enthalpy) that must be added to a liquid substance to transform a quantity of that sub ...

in MJ/kg

References

{{reflist Remote sensing