Package net.simplace.sim.components.experimental.runoff

Class RunoffSurfaceCover

java.lang.Object
net.simplace.sim.model.FWSimComponent
net.simplace.sim.components.experimental.runoff.RunoffSurfaceCover
All Implemented Interfaces:
net.simplace.sim.util.FWSimFieldContainer
public class RunoffSurfaceCover extends net.simplace.sim.model.FWSimComponent

This SimComponent calculates the surface cover fraction for runoff and erosion simulations. The algorithm follows the same formulations used in the APSIM (Agricultural Production Systems sIMulator) platform, which was adapted from the PERFECT model (Littleboy et al., 1992).

The soil cover fraction is expressed by the Beer-lambert law as a function of the leaf area index (LAI) and surface organic matter. Both variables can be obtained from a crop growth SimComponent (e.g., LintulBiomass) or prescribed in a management component. The calculation procedure for determining the surface cover fraction is described in the following equations:

\[ \begin{eqnarray} Cover_{Green} & = & 1 - e^{(-K_{Green} \cdot LAI_{Green})} \\ Cover_{Senes} & = & 1 - e^{(-K_{Senes} \cdot LAI_{Senes})} \\ Cover_{SurfOM} & = & 1 - e^{(-K_{SurfOM} \cdot LAI_{SurfOM})} \\ Cover_{Total} & = & 1 - [(1 - Cover_{Green}) \cdot (1 - Cover_{Senes})] \cdot CanHFac \\ CoverFraction & = & 1 - [(1 - Cover_{Total}) \cdot (1 - Cover_{SurfOM})] \\ \end{eqnarray} \]

Where LAIGreen (iGreenLAI) is the green LAI (m2/m2); LAISenes (iSenesLAI) is the dry LAI still attached to the crop stems (m2/m2); SurfOM (iSurfOM) is the soil surface residues (t/ha); KGreen (cGreenK), KSenes (cSenesK), and KSurfOM (cSurfOMK) are the extinction coefficients for green LAI, for senesced LAI and SurfOM, respectively (all dimensionless); CoverGreen, CoverSenes and CoverSurfOM are the respective calculated cover fractions; CoverTotal is the total cover fraction of the canopy corrected by crop height; CanHFac is the correction factor (0-1) of CoverTotal as a function of canopy height (iHeight); CoverFraction (CoverFrac) is the final soil cover fraction (0-1) taking into account the crop canopy and soil surface residues. The CanHFac is calculated using an interpolation table consisting of canopy height (cCanopyFactorsHeight) and the respective reducing factors (cCanopyFactors). The effect of height is typically neglected (e.g., CanHFac=1) when the crop height is below 60 cm.

References

APSIM v7.1 source code. Last time accessed: Dec-14-2022. URL: https://github.com/APSIMInitiative/APSIMClassic

Littleboy, M., D.M. Silburn, D.M. Freebairn, D.R. Woodruff, G.L. Hammer, and J.K. Leslie. 1992. Impact of soil erosion on production in cropping systems. I. Development and validation of a simulation model. Aust. J. Soil Res. 30, 757-774.

Holzworth, Dean P., Neil I. Huth, Peter G. deVoil, Eric J. Zurcher, Neville I. Herrmann, Greg McLean, Karine Chenu, et al. "APSIM - Evolution towards a New Generation of Agricultural Systems Simulation." Environmental Modelling & Software 62 (December 2014): 327–350. https://doi.org/10.1016/j.envsoft.2014.07.009

Author:
Murilo Vianna, Gunther Krauss, gk@uni-bonn.de

Component Variables

Content TypeNameDescriptionData TypeUnitMin ValueMax ValueDefault Value
inputcGreenKExtinction coefficient for green LAIDOUBLE10.02.00.5
inputcSenesKExtinction coefficient for senesced LAIDOUBLE10.02.00.3
inputcSurfOMKExtinction coefficient for organic matter surfaceDOUBLE10.02.00.5
inputiGreenLAIGreen Leaf Area Index (LAI)DOUBLEm2/m20.020.0-
inputiHeightCrop HeightDOUBLEmm0.010000.0-
inputiSenesLAISenesced Leaf Area Index (LAI)DOUBLEm2/m20.020.0-
inputiSurfOMSoil surface organic matterDOUBLEg/m20.0100000.0-
outCoverFracSurface cover fraction for runoff calculationsDOUBLE10.01000.0-

  • 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
    RunoffSurfaceCover()
    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)
     
    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
    process()
    Process the algorithm and write the results back to VarMap

    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

    • RunoffSurfaceCover

      public RunoffSurfaceCover()
      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()

    • 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()

    • 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)
      Specified by:
      clone in class net.simplace.sim.model.FWSimComponent
      See Also:
      • net.simplace.simulation.model.FWSimComponent#clone(net.simplace.simulation.util.FWSimVarMap)