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net.simplace.client.simulation.lap.fao56.evapotran.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	Default Value
input	iSolarRadiation	solar radiation	DOUBLE	MJ/(m2 d)	-	-	0.0
input	iTMax	maximum daily temperature	DOUBLE	°C	-	-	0.0
input	iTMin	minimum daily temperature	DOUBLE	°C	-	-	0.0
ET0	reference evapotranspiration	DOUBLE	mm/d	null

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

// Public Instance Methods

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

Create the FWSimVariables as interface for this SimComponent

// Protected Instance Methods

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

Initializes the fields by getting input and output FWSimVariables from VarMap

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

Process the algorithm and write the results back to VarMap

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

creates a clone from this SimComponent for use in other threads

}

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