Potential evaporation

Potential evaporation

Potential evaporation or potential evapotranspiration (PET) is defined as the amount of evaporation that would occur if a sufficient water source were available. If the actual evapotranspiration is considered the net result of atmospheric demand for moisture from a surface and the ability of the surface to supply moisture, then PET is a measure of the demand side. Surface and air temperatures, insolation, and wind all affect this. A dryland is a place where annual potential evaporation exceeds annual precipitation.

Estimates of potential evaporation


= Thornthwaite equation (1948) =

PET = 16 left(frac{L}{12} ight)left(frac{N}{30} ight)left(frac{10, T_a}{I} ight)^alpha

Where,

alpha = (6.75 imes 10^{-7}) I^3 - (7.71 imes 10^{-5}) I^2 + (1.79 imes 10^{-2}) I + 0.49

I = sum_{i=1}^{n} left(frac{T_{ai{5} ight)^{1.514}

Penman equation (1948)

See also

* Evaporation
* Water vapour
* Water cycle
* Köppen climate classification

References

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External links

* [http://ag.arizona.edu/~lmilich/pe.html ag.arizona.edu] Global map of potential evaporation.


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