/// <summary>Perform the overall Canopy Energy Balance</summary>
private void BalanceCanopyEnergy(MicroClimateZone MCZone)
{
ShortWaveRadiation(MCZone);
EnergyTerms(MCZone);
LongWaveRadiation(MCZone);
SoilHeatRadiation(MCZone);
}
/// <summary>Calculate the interception loss of water from the canopy</summary>
private void CalculateInterception(MicroClimateZone MCZone)
{
double sumLAI = 0.0;
double sumLAItot = 0.0;
for (int i = 0; i <= MCZone.numLayers - 1; i++)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
sumLAI += MCZone.Canopies[j].LAI[i];
sumLAItot += MCZone.Canopies[j].LAItot[i];
}
}
double totalInterception = a_interception * Math.Pow(weather.Rain, b_interception) + c_interception * sumLAItot + d_interception;
totalInterception = Math.Max(0.0, Math.Min(0.99 * weather.Rain, totalInterception));
for (int i = 0; i <= MCZone.numLayers - 1; i++)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].interception[i] = MathUtilities.Divide(MCZone.Canopies[j].LAI[i], sumLAI, 0.0) * totalInterception;
}
}
}
/// <summary>Calculate the aerodynamic decoupling for system compartments</summary>
private void CalculateOmega(MicroClimateZone MCZone)
{
for (int i = 0; i <= MCZone.numLayers - 1; i++)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].Omega[i] = CalcOmega(weather.MinT, weather.MaxT, weather.AirPressure, MCZone.Canopies[j].Ga[i], MCZone.Canopies[j].Gc[i]);
}
}
}
/// <summary>
/// This model is for strip crops where there is verticle overlap of the shortest and tallest crops canopy but no horizontal overlap
/// </summary>
/// <param name="tallest"></param>
/// <param name="shortest"></param>
private void DoStripCropShortWaveRadiation(ref MicroClimateZone tallest, ref MicroClimateZone shortest)
{
if (MathUtilities.Sum(tallest.DeltaZ) > 0) // Don't perform calculations if layers are empty
{
double Ht = MathUtilities.Sum(tallest.DeltaZ); // Height of tallest strip
double Hs = MathUtilities.Sum(shortest.DeltaZ); // Height of shortest strip
double Wt = (tallest.Zone as Zones.RectangularZone).Width; // Width of tallest strip
double Ws = (shortest.Zone as Zones.RectangularZone).Width; // Width of shortest strip
double Ft = Wt / (Wt + Ws); // Fraction of space in tallest strip
double Fs = Ws / (Wt + Ws); // Fraction of space in the shortest strip
double LAIt = MathUtilities.Sum(tallest.LAItotsum); // LAI of tallest strip
double LAIs = MathUtilities.Sum(shortest.LAItotsum); // LAI of shortest strip
double Kt = tallest.Canopies[0].Ktot; // Extinction Coefficient of the tallest strip
double Ks = shortest.Canopies[0].Ktot; // Extinction Coefficient of the shortest strip
double Httop = Ht - Hs; // Height of the top layer in tallest strip (ie distance from top of shortest to top of tallest)
double LAIttop = Httop / Ht * LAIt; // LAI of the top layer of the tallest strip (ie LAI in tallest strip above height of shortest strip)
double LAItbot = LAIt - LAIttop; // LAI of the bottom layer of the tallest strip (ie LAI in tallest strip below height of the shortest strip)
double LAIttophomo = Ft * LAIttop; // LAI of top layer of tallest strip if spread homogeneously across all of the space
double Ftblack = (Math.Sqrt(Math.Pow(Httop, 2) + Math.Pow(Wt, 2)) - Httop) / Wt; // View factor for top layer of tallest strip
double Fsblack = (Math.Sqrt(Math.Pow(Httop, 2) + Math.Pow(Ws, 2)) - Httop) / Ws; // View factor for top layer of shortest strip
double Tt = Ft * (Ftblack * Math.Exp(-Kt * LAIttop)
+ Ft * (1 - Ftblack) * Math.Exp(-Kt * LAIttophomo))
+ Fs * Ft * (1 - Fsblack) * Math.Exp(-Kt * LAIttophomo); // Transmission of light to bottom of top layer in tallest strip
double Ts = Fs * (Fsblack + Fs * (1 - Fsblack) * Math.Exp(-Kt * LAIttophomo))
+ Ft * Fs * ((1 - Ftblack) * Math.Exp(-Kt * LAIttophomo)); // Transmission of light to bottom of top layer in shortest strip
double Intttop = 1 - Tt - Ts; // Interception by the top layer of the tallest strip (ie light intercepted in tallest strip above height of shortest strip)
double Inttbot = (Tt * (1 - Math.Exp(-Kt * LAItbot))); // Interception by the bottom layer of the tallest strip
double Soilt = (Tt * (Math.Exp(-Kt * LAItbot))); // Transmission to the soil below tallest strip
double Ints = Ts * (1 - Math.Exp(-Ks * LAIs)); // Interception by the shortest strip
double Soils = Ts * (Math.Exp(-Ks * LAIs)); // Transmission to the soil below shortest strip
double EnergyBalanceCheck = Intttop + Inttbot + Soilt + Ints + Soils; // Sum of all light fractions (should equal 1)
if (Math.Abs(1 - EnergyBalanceCheck) > 0.001)
{
throw (new Exception("Energy Balance not maintained in strip crop light interception model"));
}
//tallest.Canopies[0].Rs[0] = weather.Radn * (Intttop + Inttbot) / Ft;
//tallest.SurfaceRs = weather.Radn * Soilt / Ft;
CalculateLayeredShortWaveRadiation(tallest, weather.Radn * (Intttop + Inttbot) / Ft);
// if (shortest.Canopies[0].Rs != null)
// if (shortest.Canopies[0].Rs.Length > 0)
// shortest.Canopies[0].Rs[0] = weather.Radn * Ints / Fs;
//shortest.SurfaceRs = weather.Radn * Soils / Fs;
CalculateLayeredShortWaveRadiation(shortest, weather.Radn * Ints / Fs);
}
else
{
//tallest.Canopies[0].Rs[0] =0;
tallest.SurfaceRs = weather.Radn;
//shortest.Canopies[0].Rs[0] = 0;
shortest.SurfaceRs = weather.Radn;
}
}
/// <summary>
/// Create a new MicroClimateZone for a given simulation zone
/// </summary>
/// <param name="newZone"></param>
private void CreateMCZone(Zone newZone)
{
MicroClimateZone myZone = new MicroClimateZone();
myZone.zone = newZone;
myZone.Reset();
foreach (ICanopy canopy in Apsim.ChildrenRecursively(newZone, typeof(ICanopy)))
{
myZone.Canopies.Add(new CanopyType(canopy));
}
microClimateZones.Add(myZone);
}
/// <summary>Calculate the aerodynamic conductance for system compartments</summary>
private void CalculateGa(MicroClimateZone MCZone)
{
double sumDeltaZ = MathUtilities.Sum(MCZone.DeltaZ);
double sumLAI = MathUtilities.Sum(MCZone.LAItotsum);
double totalGa = AerodynamicConductanceFAO(weather.Wind, refheight, sumDeltaZ, sumLAI);
for (int i = 0; i <= MCZone.numLayers - 1; i++)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].Ga[i] = totalGa * MathUtilities.Divide(MCZone.Canopies[j].Rs[i], MCZone.sumRs, 0.0);
}
}
}
/// <summary>
/// Calculate Radiation loss to soil heating
/// </summary>
private void SoilHeatRadiation(MicroClimateZone MCZone)
{
double radnint = MCZone.sumRs; // Intercepted SW radiation
MCZone.soil_heat = SoilHeatFlux(weather.Radn, radnint, soil_heat_flux_fraction);
// SoilHeat balance Proportional to Short Wave Balance
// ====================================================
for (int i = MCZone.numLayers - 1; i >= 0; i += -1)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].Rsoil[i] = MathUtilities.Divide(MCZone.Canopies[j].Rs[i], weather.Radn, 0.0) * MCZone.soil_heat;
}
}
}
/// <summary>
/// Calculates interception of short wave by canopy compartments
/// </summary>
private void CalculateShortWaveRadiation(MicroClimateZone MCZone)
{
// Perform Top-Down Light Balance
// ==============================
double Rin = weather.Radn;
double Rint = 0;
for (int i = MCZone.numLayers - 1; i >= 0; i += -1)
{
Rint = Rin * (1.0 - Math.Exp(-MCZone.layerKtot[i] * MCZone.LAItotsum[i]));
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].Rs[i] = Rint * MathUtilities.Divide(MCZone.Canopies[j].Ftot[i] * MCZone.Canopies[j].Ktot, MCZone.layerKtot[i], 0.0);
}
Rin -= Rint;
}
}
/// <summary>Calculate the canopy conductance for system compartments</summary>
private void CalculateGc(MicroClimateZone MCZone)
{
double Rin = weather.Radn;
for (int i = MCZone.numLayers - 1; i >= 0; i += -1)
{
double Rflux = Rin * 1000000.0 / (dayLength * hr2s) * (1.0 - MCZone._albedo);
double Rint = 0.0;
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].Gc[i] = CanopyConductance(MCZone.Canopies[j].Canopy.Gsmax, MCZone.Canopies[j].Canopy.R50, MCZone.Canopies[j].Canopy.FRGR, MCZone.Canopies[j].Fgreen[i], MCZone.layerKtot[i], MCZone.LAItotsum[i], Rflux);
Rint += MCZone.Canopies[j].Rs[i];
}
// Calculate Rin for the next layer down
Rin -= Rint;
}
}
/// <summary>
/// Calculate Net Long Wave Radiation Balance
/// </summary>
private void LongWaveRadiation(MicroClimateZone MCZone)
{
double sunshineHours = CalcSunshineHours(weather.Radn, dayLengthLight, weather.Latitude, Clock.Today.DayOfYear);
double fractionClearSky = MathUtilities.Divide(sunshineHours, dayLengthLight, 0.0);
double averageT = CalcAverageT(weather.MinT, weather.MaxT);
MCZone.NetLongWaveRadiation = LongWave(averageT, fractionClearSky, emissivity) * dayLength * hr2s / 1000000.0; // W to MJ
// Long Wave Balance Proportional to Short Wave Balance
// ====================================================
for (int i = MCZone.numLayers - 1; i >= 0; i += -1)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone.Canopies[j].Rl[i] = MathUtilities.Divide(MCZone.Canopies[j].Rs[i], weather.Radn, 0.0) * MCZone.NetLongWaveRadiation;
}
}
}
/// <summary>
/// Calculate the overall system energy terms
/// </summary>
private void EnergyTerms(MicroClimateZone MCZone)
{
MCZone.sumRs = 0.0;
MCZone._albedo = 0.0;
emissivity = 0.0;
for (int i = MCZone.numLayers - 1; i >= 0; i += -1)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
MCZone._albedo += MathUtilities.Divide(MCZone.Canopies[j].Rs[i], weather.Radn, 0.0) * MCZone.Canopies[j].Canopy.Albedo;
emissivity += MathUtilities.Divide(MCZone.Canopies[j].Rs[i], weather.Radn, 0.0) * Emissivity;
MCZone.sumRs += MCZone.Canopies[j].Rs[i];
}
}
MCZone._albedo += (1.0 - MathUtilities.Divide(MCZone.sumRs, weather.Radn, 0.0)) * soil_albedo;
emissivity += (1.0 - MathUtilities.Divide(MCZone.sumRs, weather.Radn, 0.0)) * soil_emissivity;
}
/// <summary>
/// Calculates interception of short wave by canopy compartments
/// </summary>
private void CalculateLayeredShortWaveRadiation(MicroClimateZone ZoneMC, double Rin)
{
// Perform Top-Down Light Balance
// ==============================
double Rint = 0;
for (int i = ZoneMC.numLayers - 1; i >= 0; i += -1)
{
if (double.IsNaN(Rint))
{
throw new Exception("Bad Radiation Value in Light partitioning");
}
Rint = Rin * (1.0 - Math.Exp(-ZoneMC.layerKtot[i] * ZoneMC.LAItotsum[i]));
for (int j = 0; j <= ZoneMC.Canopies.Count - 1; j++)
{
ZoneMC.Canopies[j].Rs[i] = Rint * MathUtilities.Divide(ZoneMC.Canopies[j].Ftot[i] * ZoneMC.Canopies[j].Ktot, ZoneMC.layerKtot[i], 0.0);
}
Rin -= Rint;
}
ZoneMC.SurfaceRs = Rin;
}
/// <summary>Send an energy balance event</summary>
private void SetCanopyEnergyTerms(MicroClimateZone MCZone)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
if (MCZone.Canopies[j].Canopy != null)
{
CanopyEnergyBalanceInterceptionlayerType[] lightProfile = new CanopyEnergyBalanceInterceptionlayerType[MCZone.numLayers];
double totalPotentialEp = 0;
double totalInterception = 0.0;
for (int i = 0; i <= MCZone.numLayers - 1; i++)
{
lightProfile[i] = new CanopyEnergyBalanceInterceptionlayerType();
lightProfile[i].thickness = MCZone.DeltaZ[i];
lightProfile[i].amount = MCZone.Canopies[j].Rs[i] * MCZone.RadnGreenFraction(j);
totalPotentialEp += MCZone.Canopies[j].PET[i];
totalInterception += MCZone.Canopies[j].interception[i];
}
MCZone.Canopies[j].Canopy.PotentialEP = totalPotentialEp;
MCZone.Canopies[j].Canopy.LightProfile = lightProfile;
}
}
}
/// <summary>Calculate the Penman-Monteith water demand</summary>
private void CalculatePM(MicroClimateZone MCZone)
{
// zero a few things, and sum a few others
double sumRl = 0.0;
double sumRsoil = 0.0;
double sumInterception = 0.0;
double freeEvapGa = 0.0;
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
sumRl += MathUtilities.Sum(MCZone.Canopies[j].Rl);
sumRsoil += MathUtilities.Sum(MCZone.Canopies[j].Rsoil);
sumInterception += MathUtilities.Sum(MCZone.Canopies[j].interception);
freeEvapGa += MathUtilities.Sum(MCZone.Canopies[j].Ga);
}
double netRadiation = ((1.0 - MCZone._albedo) * MCZone.sumRs + sumRl + sumRsoil) * 1000000.0; // MJ/J
netRadiation = Math.Max(0.0, netRadiation);
double freeEvapGc = freeEvapGa * 1000000.0; // infinite surface conductance
double freeEvap = CalcPenmanMonteith(netRadiation, weather.MinT, weather.MaxT, weather.VP, weather.AirPressure, dayLength, freeEvapGa, freeEvapGc);
MCZone.dryleaffraction = 1.0 - MathUtilities.Divide(sumInterception * (1.0 - night_interception_fraction), freeEvap, 0.0);
MCZone.dryleaffraction = Math.Max(0.0, MCZone.dryleaffraction);
for (int i = 0; i <= MCZone.numLayers - 1; i++)
{
for (int j = 0; j <= MCZone.Canopies.Count - 1; j++)
{
netRadiation = 1000000.0 * ((1.0 - MCZone._albedo) * MCZone.Canopies[j].Rs[i] + MCZone.Canopies[j].Rl[i] + MCZone.Canopies[j].Rsoil[i]);
netRadiation = Math.Max(0.0, netRadiation);
MCZone.Canopies[j].PETr[i] = CalcPETr(netRadiation * MCZone.dryleaffraction, weather.MinT, weather.MaxT, weather.AirPressure, MCZone.Canopies[j].Ga[i], MCZone.Canopies[j].Gc[i]);
MCZone.Canopies[j].PETa[i] = CalcPETa(weather.MinT, weather.MaxT, weather.VP, weather.AirPressure, dayLength * MCZone.dryleaffraction, MCZone.Canopies[j].Ga[i], MCZone.Canopies[j].Gc[i]);
MCZone.Canopies[j].PET[i] = MCZone.Canopies[j].PETr[i] + MCZone.Canopies[j].PETa[i];
}
}
}
/// <summary>
/// This model is for tree crops where there is no vertical overlap of the shortest and tallest canopy but the tallest canopy can overlap the shortest horzontally
/// </summary>
/// <param name="tree"></param>
/// <param name="alley"></param>
private void DoTreeRowCropShortWaveRadiation(ref MicroClimateZone tree, ref MicroClimateZone alley)
{
if (MathUtilities.Sum(tree.DeltaZ) > 0) // Don't perform calculations if layers are empty
{
double Ht = MathUtilities.Sum(tree.DeltaZ); // Height of tree canopy
double CDt = 0; //tree.Canopies[0].Canopy.Depth / 1000; // Depth of tree canopy
foreach (MicroClimateCanopy c in tree.Canopies)
{
if (c.Canopy.Depth < c.Canopy.Height)
{
if (CDt > 0.0)
{
throw new Exception("Can't have two tree canopies");
}
else
{
CDt = c.Canopy.Depth / 1000;
}
}
}
double CBHt = Ht - CDt; // Base hight of the tree canopy
double Ha = MathUtilities.Sum(alley.DeltaZ); // Height of alley canopy
if ((Ha > CBHt) & (tree.DeltaZ.Length > 1))
{
throw (new Exception("Height of the alley canopy must not exceed the base height of the tree canopy"));
}
double Wt = (tree.Zone as Zones.RectangularZone).Width; // Width of tree zone
double Wa = (alley.Zone as Zones.RectangularZone).Width; // Width of alley zone
double CWt = 0; //Math.Min(tree.Canopies[0].Canopy.Width / 1000, (Wt + Wa));// Width of the tree canopy
foreach (MicroClimateCanopy c in tree.Canopies)
{
if (c.Canopy.Depth < c.Canopy.Height)
{
if (CWt > 0.0)
{
throw new Exception("Can't have two tree canopies");
}
else
{
CWt = Math.Min(c.Canopy.Width / 1000, (Wt + Wa));
}
}
}
double WaOl = Math.Min(CWt - Wt, Wa); // Width of tree canopy that overlap the alley zone
double WaOp = Wa - WaOl; // Width of the open alley zone between tree canopies
double Ft = CWt / (Wt + Wa); // Fraction of space in tree canopy
double Fs = WaOp / (Wt + Wa); // Fraction of open space in the alley row
double LAIt = MathUtilities.Sum(tree.LAItotsum); // LAI of trees
double LAIa = MathUtilities.Sum(alley.LAItotsum); // LAI of alley crop
double Kt = tree.Canopies[0].Ktot; // Extinction Coefficient of trees
double Ka = alley.Canopies[0].Ktot; // Extinction Coefficient of alley crop
double LAIthomo = Ft * LAIt; // LAI of trees if spread homogeneously across row and alley zones
double Ftbla = (Math.Sqrt(Math.Pow(CDt, 2) + Math.Pow(CWt, 2)) - CDt) / CWt; // View factor for the tree canopy if a black body
double Fabla = (Math.Sqrt(Math.Pow(CDt, 2) + Math.Pow(WaOp, 2)) - CDt) / WaOp; // View factor for the gap between trees in alley if trees a black body
if (WaOp == 0)
{
Fabla = 0;
}
//All transmission and interception values below are a fraction of the total short wave radiation incident to both the tree and alley rows
double Tt = Ft * (Ftbla * Math.Exp(-Kt * LAIt)
+ Ft * (1 - Ftbla) * Math.Exp(-Kt * LAIthomo))
+ Fs * Ft * (1 - Fabla) * Math.Exp(-Kt * LAIthomo); // Transmission of light to the bottom of the tree canopy
double Ta = Fs * (Fabla + Fs * (1 - Fabla) * Math.Exp(-Kt * LAIthomo))
+ Ft * Fs * ((1 - Ftbla) * Math.Exp(-Kt * LAIthomo)); // Transmission of light to the bottom of the gap in the tree canopy
double It = 1 - Tt - Ta; // Interception by the trees
double St = Tt * Wt / CWt; // Transmission to the soil in the tree zone
double IaOl = Tt * WaOl / CWt * (1 - Math.Exp(-Ka * LAIa)); // Interception by the alley canopy below the overlap of the trees
double IaOp = Ta * (1 - Math.Exp(-Ka * LAIa)); // Interception by the alley canopy in the gaps between tree canopy
double Ia = IaOl + IaOp; // Interception by the alley canopy
double SaOl = Tt * WaOl / CWt * (Math.Exp(-Ka * LAIa)); // Transmission to the soil beneigth the alley canopy under the tree canopy
double SaOp = Ta * (Math.Exp(-Ka * LAIa)); // Transmission to the soil beneigth the alley canopy in the open
double Sa = SaOl + SaOp; // Transmission to the soil beneight the alley
double EnergyBalanceCheck = It + St + Ia + Sa; // Sum of all light fractions (should equal 1)
if (Math.Abs(1 - EnergyBalanceCheck) > 0.001)
{
throw (new Exception("Energy Balance not maintained in strip crop light interception model"));
}
Ft = (Wt) / (Wt + Wa); // Remove overlap so scaling back to zone ground area works
Fs = (Wa) / (Wt + Wa); // Remove overlap so scaling back to zone ground area works
CalculateLayeredShortWaveRadiation(tree, weather.Radn * It / Ft);
CalculateLayeredShortWaveRadiation(alley, weather.Radn * Ia / Fs);
}
else
{
tree.SurfaceRs = weather.Radn;
CalculateLayeredShortWaveRadiation(alley, weather.Radn);
}
}
/// <summary>
/// This model is for strip crops where there is no verticle overlap of the shortest and tallest crops canopy but no horizontal overlap
/// </summary>
/// <param name="vine"></param>
/// <param name="alley"></param>
private void DoVineStripShortWaveRadiation(ref MicroClimateZone vine, ref MicroClimateZone alley)
{
if (MathUtilities.Sum(vine.DeltaZ) > 0) // Don't perform calculations if layers are empty
{
double Ht = MathUtilities.Sum(vine.DeltaZ); // Height of tree canopy
double CDt = vine.Canopies[0].Canopy.Depth / 1000; // Depth of tree canopy
double CBHt = Ht - CDt; // Base hight of the tree canopy
double Ha = MathUtilities.Sum(alley.DeltaZ); // Height of alley canopy
if ((Ha > CBHt) & (vine.DeltaZ.Length > 1))
{
throw (new Exception("Height of the alley canopy must not exceed the base height of the tree canopy"));
}
double Wt = (vine.Zone as Zones.RectangularZone).Width; // Width of tree zone
double Wa = (alley.Zone as Zones.RectangularZone).Width; // Width of alley zone
double CWt = vine.Canopies[0].Canopy.Width / 1000; // Width of the tree canopy
double WaOl = (CWt + Wt) / 2; //adjusted Width of tree canopy, because the tree canopy is smaller than the strip width, so there would be a gap between alley and tree
double WaOp = Wa + Wt - WaOl; // Width of the open alley zone between tree canopies
double Ft = WaOl / (Wt + Wa); // Fraction of space in tree canopy
double Fs = WaOp / (Wt + Wa); // Fraction of open space in the alley row
double LAIt = MathUtilities.Sum(vine.LAItotsum); // LAI of tallest strip
double LAIs = MathUtilities.Sum(alley.LAItotsum); // LAI of shortest strip
double Kt = 0; // Extinction Coefficient of the tallest strip
if (vine.Canopies.Count > 0) // If it exists...
{
Kt = vine.Canopies[0].Ktot;
}
double Ka = 0; // Extinction Coefficient of the shortest strip
if (alley.Canopies.Count > 0) // If it exists...
{
Ka = alley.Canopies[0].Ktot;
}
double Httop = Ht - Ha; // distance from top of shortest to top of tallest
double LAIthomo = Ft * LAIt; // LAI of top layer of tallest strip if spread homogeneously across all of the space
double Ftblack = (Math.Sqrt(Math.Pow(CDt, 2) + Math.Pow(WaOl, 2)) - CDt) / WaOl; // View factor for top layer of tallest strip
double Fsblack = (Math.Sqrt(Math.Pow(Httop, 2) + Math.Pow(WaOp, 2)) - Httop) / WaOp; // View factor for top layer of shortest strip
double Tt = Ft * (Ftblack * Math.Exp(-Kt * LAIt)
+ Ft * (1 - Ftblack) * Math.Exp(-Kt * LAIthomo))
+ Fs * Ft * (1 - Fsblack) * Math.Exp(-Kt * LAIthomo); // Transmission of light to bottom of top layer in tallest strip
double Ts = Fs * (Fsblack + Fs * (1 - Fsblack) * Math.Exp(-Kt * LAIthomo))
+ Ft * Fs * ((1 - Ftblack) * Math.Exp(-Kt * LAIthomo)); // Transmission of light to bottom of top layer in shortest strip
double Intttop = 1 - Tt - Ts; // Interception by the top layer of the tallest strip (ie light intercepted in tallest strip above height of shortest strip)
double Inttbot = (Tt * (1 - Math.Exp(-Kt * 0))); // Interception by the bottom layer of the tallest strip
double Soilt = (Tt * (Math.Exp(-Kt * 0))); // Transmission to the soil below tallest strip
double Ints = Ts * (1 - Math.Exp(-Ka * LAIs)); // Interception by the shortest strip
double Soils = Ts * (Math.Exp(-Ka * LAIs)); // Transmission to the soil below shortest strip
double EnergyBalanceCheck = Intttop + Inttbot + Soilt + Ints + Soils; // Sum of all light fractions (should equal 1)
if (Math.Abs(1 - EnergyBalanceCheck) > 0.001)
{
throw (new Exception("Energy Balance not maintained in strip crop light interception model"));
}
Ft = (Wt) / (Wt + Wa); // Remove overlap so scaling back to zone ground area works
Fs = (Wa) / (Wt + Wa); // Remove overlap so scaling back to zone ground area works
if (vine.Canopies.Count > 0)
{
vine.Canopies[0].Rs[0] = weather.Radn * (Intttop + Inttbot) / Ft;
}
vine.SurfaceRs = weather.Radn * Soilt / Ft;
if (alley.Canopies.Count > 0 && alley.Canopies[0].Rs != null)
{
if (alley.Canopies[0].Rs.Length > 0)
{
alley.Canopies[0].Rs[0] = weather.Radn * Ints / Fs;
}
}
alley.SurfaceRs = weather.Radn * Soils / Fs;
}
else
{
//tallest.Canopies[0].Rs[0] =0;
vine.SurfaceRs = weather.Radn;
//shortest.Canopies[0].Rs[0] = 0;
alley.SurfaceRs = weather.Radn;
}
}
/// <summary>
/// This model is for strip crops where there is no verticle overlap of the shortest and tallest crops canopy but no horizontal overlap
/// </summary>
/// <param name="vine"></param>
/// <param name="alley"></param>
private void DoVineStripShortWaveRadiation(ref MicroClimateZone vine, ref MicroClimateZone alley)
{
if (vine.DeltaZ.Sum() > 0) // Don't perform calculations if layers are empty
{
double Ht = vine.DeltaZ.Sum(); // Height of tree canopy
double CDt = vine.Canopies[0].Canopy.Depth / 1000; // Depth of tree canopy
double CBHt = Ht - CDt; // Base hight of the tree canopy
double Ha = alley.DeltaZ.Sum(); // Height of alley canopy
if ((Ha > CBHt) & (vine.DeltaZ.Length > 1))
{
throw (new Exception("Height of the alley canopy must not exceed the base height of the tree canopy"));
}
double Wt = (vine.Zone as Zones.RectangularZone).Width; // Width of tree zone
double Wa = (alley.Zone as Zones.RectangularZone).Width; // Width of alley zone
double CWt = vine.Canopies[0].Canopy.Width / 1000; // Width of the tree canopy
double WaOp = Wa + Wt - CWt; // Width of the open alley zone between tree canopies
double Ft = CWt / (Wt + Wa); // Fraction of space in tree canopy
double Fs = WaOp / (Wt + Wa); // Fraction of open space in the alley row
double LAIt = vine.LAItotsum.Sum() * Wt / CWt; // adjusting the LAI of tallest strip based on new width
double LAIs = alley.LAItotsum.Sum() * Wa / WaOp; // adjusting the LAI of shortest strip based on new width
double Kt = 0; // Extinction Coefficient of the tallest strip
if (vine.Canopies.Count > 0 & LAIt > 0) // If it exists...
{
Kt = vine.Canopies[0].Ktot;
}
double Ka = 0; // Extinction Coefficient of the shortest strip
if (alley.Canopies.Count > 0 & LAIs > 0) // If it exists...
{
Ka = alley.Canopies[0].Ktot;
}
double Httop = Ht - Ha; // distance from top of shortest to top of tallest
double LAIthomo = Ft * LAIt; // LAI of top layer of tallest strip if spread homogeneously across all of the space
double fhomo = 1 - Math.Exp(-Kt * LAIthomo);
double fcompr = (1 - Math.Exp(-Kt * LAIt)) * CWt / WaOp;
double IPblackt = (Math.Sqrt(Math.Pow(CDt, 2) + Math.Pow(WaOp, 2)) - CDt) / WaOp;
double IRblackt = (Math.Sqrt(Math.Pow(CDt, 2) + Math.Pow(CWt, 2)) - CDt) / CWt; // View factor for top layer of tallest strip
double SPt = IPblackt + (1 - IPblackt) * Math.Exp(-Kt * LAIthomo);
double SRt = IRblackt * Math.Exp(-Kt * LAIt) +
(1 - IRblackt) * Math.Exp(-Kt * LAIthomo); // Transmission of light to bottom of top layer in tallest strip
double W = 0;
if (vine.Canopies.Count > 0 & LAIt > 0 & Kt > 0) // If it exists...
{
W = (SPt - SRt) / (1 - Math.Exp(-Kt * LAIt));
}
double ftop = fhomo * (1 - W) + fcompr * W; // light interception by the vine row
//use different height and LAI distribution for calculating the light penetrate to the interrow
//this is for accounting the effect of trunk, cordon, and post that shading on the interrow
double IPblackb = (Math.Sqrt(Math.Pow(Httop, 2) + Math.Pow(WaOp, 2)) - Httop) / WaOp; //bottom part
double IRblackb = (Math.Sqrt(Math.Pow(Httop, 2) + Math.Pow(CWt, 2)) - Httop) / CWt; // View factor for top layer of tallest strip
double SPb = IPblackb + (1 - IPblackb) * Math.Exp(-Kt * LAIthomo);
double SRb = IRblackb * Math.Exp(-Kt * LAIt) +
(1 - IRblackb) * Math.Exp(-Kt * LAIthomo); // Transmission of light to bottom of top layer in tallest strip
//double Wb = (SPt - SRt) / (1 - Math.Exp(-Kt * LAIt));
//double fb = fhomo * (1 - W) + fcompr * W; //light interception by the vine row
double Soilt = SRb * Ft; // Transmission to the soil below tallest strip
double Intttop = ftop; // Interception by the top layer of the tallest strip (ie light intercepted in tallest strip above height of shortest strip)
double Ints = SPb * (1 - Math.Exp(-Ka * LAIs)) * Fs; // Interception by the shortest strip
double Soils = SPb * (Math.Exp(-Ka * LAIs)) * Fs; // Transmission to the soil below shortest strip
Ft = (Wt) / (Wt + Wa); // Scaling back to zone ground area works
Fs = (Wa) / (Wt + Wa); // Scaling back to zone ground area works
// Perform Top-Down Light Balance for tree zone
// ==============================
double Rint = 0;
double Rin = weather.Radn * Intttop / Ft;
for (int i = vine.numLayers - 1; i >= 0; i += -1)
{
if (double.IsNaN(Rint))
{
throw new Exception("Bad Radiation Value in Light partitioning");
}
Rint = Rin;
for (int j = 0; j <= vine.Canopies.Count - 1; j++)
{
vine.Canopies[j].Rs[i] = Rint * MathUtilities.Divide(vine.Canopies[j].Ftot[i] * vine.Canopies[j].Ktot, vine.layerKtot[i], 0.0);
}
Rin -= Rint;
}
vine.SurfaceRs = weather.Radn * Soilt / Ft;
// Perform Top-Down Light Balance for alley zone
// ==============================
Rint = 0;
Rin = weather.Radn * Ints / Fs;
for (int i = alley.numLayers - 1; i >= 0; i += -1)
{
if (double.IsNaN(Rint))
{
throw new Exception("Bad Radiation Value in Light partitioning");
}
Rint = Rin;
for (int j = 0; j <= alley.Canopies.Count - 1; j++)
{
alley.Canopies[j].Rs[i] = Rint * MathUtilities.Divide(alley.Canopies[j].Ftot[i] * alley.Canopies[j].Ktot, alley.layerKtot[i], 0.0);
}
Rin -= Rint;
}
alley.SurfaceRs = weather.Radn * Soils / Fs;
}
else
{
//tallest.Canopies[0].Rs[0] =0;
vine.SurfaceRs = weather.Radn;
//shortest.Canopies[0].Rs[0] = 0;
alley.SurfaceRs = weather.Radn;
}
}