Package net.simplace.usermodules.ET_Study

Class CropEvapoTranspirationDualCoeff

java.lang.Object

net.simplace.sim.model.FWSimComponent

net.simplace.usermodules.ET_Study.CropEvapoTranspirationDualCoeff

All Implemented Interfaces:

net.simplace.sim.util.FWSimFieldContainer

public class CropEvapoTranspirationDualCoeff
extends net.simplace.sim.model.FWSimComponent

Calculates the basal crop coefficient and the soil evaporation coefficient, as well as potential crop transpiration and potential soil evaporation using formulas from (FAO 56).

For calculations following daily inputs are needed

• ET0 reference crop evapotranspiration
• LAI leaf area index
• DVS development stage of the plant
• K_r evaporation reduction factor due to depletion of the upper soil layer
• K_s transpiration reduction factor due to water stress

When K_r is not available, then a value of 1 is used. In this case one might use the outputs KeUpper, PotentialSoilEvaporationUpper and ETCUpper instead of Ke, PotentialSoilEvaporation and ETC. (??? - if no K_r given, what should be used: Ke with K_r=1 or KeUpper?)

If development stage is less than 0.001, then Kcb is set to the initial value KcbIni. Otherwise Kcb is set to KcbMidLAI, which is calculated according to (FAO 56). (??? - is there any reference for this proceeding)

For full documentation of the formulas please check the orginal reference (FAO 56)

References: Allen et al., 1996. Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56, 1998 http://www.fao.org/docrep/x0490e/x0490e00.htm

Author:

Heidi Webber, Gunther Krauss, gk@uni-bonn.de, Roelof Oomen

Component Variables

Content Type	Name	Description	Data Type	Unit	Min Value	Max Value	Default Value
constant	cCharacteristicMeanRelHumidity	region's characteristic mean daily min relative humidity for mid/late growth season	DOUBLE	%	0.0	100.0	45.0
constant	cCharacteristicWindSpeed	region's characteristic wind speed at 2m during the mid growing season m s-1	DOUBLE	m/s	0.0	-	2.0
constant	cCropHeight	average crop height during mid/late season	DOUBLE	m	0.0	5.0	0.0
constant	cKcMin	min Kc for dry bare soil with no ground cover	DOUBLE	1	0.0	2.0	0.15
constant	cKcbIni	nominal Kcb value during initial growth stage	DOUBLE	1	0.0	2.0	0.0
constant	cKcbMid	nominal peak Kcb value obtained during mid season growth stage	DOUBLE	1	0.0	2.0	0.0
constant	cWettedSoilFraction	fraction of soil surface wetted by rain or irrigation	DOUBLE	1	0.0	1.0	1.0
constant	iK_r	Evaporation reduction coefficient (optional, if null no ActualSoilEvapCrop is calculated)	DOUBLE	1	0.0	1.0	-
constant	if_c	Covered soil fraction (optional - normally calculated from crop height)	DOUBLE	1	0.0	1.0	-
input	iDVS	daily value of development stage	DOUBLE	1	0.0	2.5	0.0
input	iDoHarvest	harvesting	BOOLEAN	1	-	-	false
input	iDoSow	sowing	BOOLEAN	1	-	-	false
input	iET0	reference crop evapotranspiration	DOUBLE	mm	0.0	20.0	0.0
input	iLAI	daily estimated leaf area index	DOUBLE	1	0.0	20.0	0.0
out	ActualSoilEvapCrop	Actual rate of evaporation from the soil	DOUBLE	mm/d	0.0	20.0	-
out	ETC	Crop ET under standard conditions if K_r is supplied (no water, nutrient, weed, pest or disease limitations to growth)	DOUBLE	mm/d	0.0	20.0	-
out	ETCUpper	Upper limit (no evaporation reduction K_r) of crop ET under standard (or - when K_s is set - water stress) conditions (no nutrient, weed, pest or disease limitations to growth)	DOUBLE	mm/d	0.0	20.0	-
out	Kcb	Basal crop coefficient	DOUBLE	1	0.0	2.0	-
out	Ke	Soil evaporation coefficient	DOUBLE	1	0.0	2.0	-
out	KeUpper	Upper limit of soil evaporation coefficient (no evaporation reduction K_r)	DOUBLE	1	0.0	2.0	-
out	PotentialSoilEvapCrop	Potential rate of evaporation from the soil	DOUBLE	mm/d	0.0	20.0	-
out	PotentialTranCrop	Potential rate of transpiration from the crop	DOUBLE	mm/d	0.0	20.0	-

Nested Class Summary

Nested classes/interfaces inherited from class net.simplace.sim.model.FWSimComponent

net.simplace.sim.model.FWSimComponent.TEST_STATE

Field Summary

Fields inherited from class net.simplace.sim.model.FWSimComponent

iFieldMap, iFrequence, iInputMap, iJexlRule, iMasterComponentGroup, iName, iOrderNumber, isComponentGroup, iSimComponentElement, iSimModel, iVarMap

Constructor Summary

Constructors

Constructor	Description
CropEvapoTranspirationDualCoeff()	Empty constructor used by class.forName()

Method Summary

Modifier and Type	Method	Description
protected net.simplace.sim.model.FWSimComponent	clone(net.simplace.sim.util.FWSimVarMap aVarMap)	/** creates a clone from this SimComponent for use in other threads
HashMap<String,net.simplace.sim.util.FWSimVariable<?>>	createVariables()	Create the FWSimVariables as interface for this SimComponent
HashMap<String,net.simplace.sim.util.FWSimVariable<?>>	fillTestVariables(int aParamIndex, net.simplace.sim.model.FWSimComponent.TEST_STATE aDefineOrCheck)	called for single component test to check the components algorithm.
protected void	init()	Initialises the fields by getting input and output FWSimVariables from VarMap
protected void	initValues()
protected void	PotTran()	Calculates K_cb and potential transpiration of crop
protected void	process()	Process the algorithm and write the results back to VarMap
protected void	resetOnHarvest()
protected void	SoilEvap()	Calculates K_e and potential soil evaporation

Methods inherited from class net.simplace.sim.model.FWSimComponent

addVariable, bind, checkCondition, createSimComponent, createSimComponent, createSimComponent, createSimComponent, doProcess, getConstantVariables, getContentType, getCreateFormXML, getDescription, getEditFormXML, getFieldMap, getFrequence, getFrequenceRuleScript, getInputs, getInputVariables, getMasterComponentGroup, getName, getOrderNumber, getOutputVariables, getVariable, getVariableField, getVarMap, initialize, isConditionCheck, isVariableAvailable, performLinks, performLinks, readInputs, removeVariable, reset, runComponentTest, setVariablesDefault, toComponentLinkingXML, toDocXML, toGroupXML, toOutputDefinitionXML, toResourcesDataXML, toResourcesDefinitionXML, toString, toXML, writeVarInfos

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

CropEvapoTranspirationDualCoeff

public CropEvapoTranspirationDualCoeff()

Empty constructor used by class.forName()

Method Details

createVariables

public HashMap<String,net.simplace.sim.util.FWSimVariable<?>> createVariables()

Create the FWSimVariables as interface for this SimComponent

Specified by:

createVariables in interface net.simplace.sim.util.FWSimFieldContainer

Specified by:

createVariables in class net.simplace.sim.model.FWSimComponent

See Also:

• net.simplace.simulation.model.FWSimComponent#createVariables()

init

protected void init()

Initialises the fields by getting input and output FWSimVariables from VarMap

Specified by:

init in class net.simplace.sim.model.FWSimComponent

See Also:

• net.simplace.simulation.model.FWSimComponent#init()

initValues

protected void initValues()

resetOnHarvest

protected void resetOnHarvest()

process

protected void process()

Process the algorithm and write the results back to VarMap

Specified by:

process in class net.simplace.sim.model.FWSimComponent

See Also:

• net.simplace.simulation.model.FWSimComponent#process()

PotTran

protected void PotTran()

Calculates K_cb and potential transpiration of crop

SoilEvap

protected void SoilEvap()

Calculates K_e and potential soil evaporation

fillTestVariables

public HashMap<String,net.simplace.sim.util.FWSimVariable<?>> fillTestVariables(int aParamIndex,
 net.simplace.sim.model.FWSimComponent.TEST_STATE aDefineOrCheck)

called for single component test to check the components algorithm.

Specified by:

fillTestVariables in class net.simplace.sim.model.FWSimComponent

See Also:

• net.simplace.sim.util.FWSimFieldContainer#fillTestVariables(int aParamIndex, TEST_STATE aDefineOrCheck)

clone

protected net.simplace.sim.model.FWSimComponent clone(net.simplace.sim.util.FWSimVarMap aVarMap)

/** creates a clone from this SimComponent for use in other threads

Specified by:

clone in class net.simplace.sim.model.FWSimComponent

See Also:

• net.simplace.simulation.model.FWSimComponent#clone(net.simplace.simulation.util.FWSimVarMap)