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net.simplace.sim.components.evapotran.fao56.ReferenceETHargreaves

Calculates reference evapotranspiration ET0 by Hargreaves method using solar radiation and temperature

Hargreaves 1975

Uses the Hargreaves 1975 formula for ET0 calculation from temperature and solar radiation

\( ET0 = 0.135 (MeanTemperature + 17.8) SolarRadiation \)

Notice: Hargreaves & Sarmani 1985

The Hargreaves & Sarmani 1985 formula is

\( ET0 = 0.0023(MeanTemperature + 17.8) \sqrt{MaxTemp - MinTemp} \cdot ExtraterrestrialRadiation \)

To calculate this formula, use SolarRadiationFromTemperature module together with ReferenceETHargreaves)

References

Hargreaves G. H. 1975. Moisture availability and crop production. Transactions of the American Society of Agricultural Engineers 18:980–984.
Hargreaves G. H. and Z. A. Samani, 1985. Reference crop evapotranspiration from temperature. Appl. Eng. Agric. 1, 96-99.

Component Variables

Content Type	Name	Description	Data Type	Unit	Min Value	Max Value
input	iSolarRadiation	solar radiation	DOUBLE	MJ/(m2 d)	-	-
input	iTMax	maximum daily temperature	DOUBLE	°C	-	-
input	iTMin	minimum daily temperature	DOUBLE	°C	-	-
out	ReferenceCropEvapotranspiration	reference evapotranspiration (ET0)	DOUBLE	mm/d	-	-

public class ReferenceETHargreaves extends net.simplace.sim.model.FWSimComponent {
// Public Constructors
public ReferenceETHargreaves();

// Public Instance Methods

public HashMap createVariables(); // Defines
net.simplace.sim.model.FWSimComponent

Create the FWSimVariables as interface for this SimComponent

// Protected Instance Methods

protected void init(); // Defines net.simplace.sim.model.FWSimComponent

Initializes the fields by getting input and output FWSimVariables from VarMap

protected void process(); // Defines net.simplace.sim.model.FWSimComponent

Process the algorithm and write the results back to VarMap

protected FWSimComponent clone(FWSimVarMap aVarMap);
// Defines net.simplace.sim.model.FWSimComponent

creates a clone from this SimComponent for use in other threads

}

Hierarchy: java.lang.Object - net.simplace.sim.model.FWSimComponent (net.simplace.sim.util.FWSimFieldContainer) - ReferenceETHargreaves