medfate (version 0.7.4)

hydrology.soilInfiltration: Soil infiltration and bare soil evaporation

Description

Function hydrology.soilInfiltration calculates the amount of water that infiltrates into the topsoil, according to the USDA SCS curve number method (Boughton 1989). The remaining is assumed to be lost as surface runoff. Function hydrology.soilEvaporation calculates the amount of evaporation from bare soil, following Ritchie (1972).

Usage

hydrology.soilInfiltration(input, Ssoil) 
hydrology.soilEvaporation(DEF,PETs, Gsoil)
hydrology.infiltrationRepartition(I, dVec, macro)

Arguments

input

A numeric vector of (daily) water input (in mm of water).

Ssoil

Soil water storage capacity (can be referred to topsoil) (in mm of water).

DEF

Water deficit in the (topsoil) layer.

PETs

Potential evapotranspiration at the soil surface.

Gsoil

Gamma parameter (maximum daily evaporation).

I

Soil infiltration (in mm of water).

dVec

Width of soil layers (in mm).

macro

Macroporosity of soil layers (in %).

Value

Function hydrology.soilInfiltration a vector of the same length as input containing the daily amount of water that infiltrates into the soil (in mm of water). Function hydrology.soilEvaporation returns the amount of water evaporated from the soil. Function hydrology.infiltrationRepartition estimates the amount of infiltrated water that reaches each soil layer.

Details

See description of infiltration and soil evaporation processes in De Caceres et al. (submitted).

References

Boughton (1989). A review of the USDA SCS curve number method. - Australian Journal of Soil Research 27: 511-523.

De C<U+00E1>ceres M, Mart<U+00ED>nez-Vilalta J, Coll L, Llorens P, Casals P, Poyatos R, Pausas JG, Brotons L. (submitted) Coupling a water balance model with forest inventory data to evaluate plant drought stress at the regional level. Agricultural and Forest Meteorology.

Ritchie (1972). Model for predicting evaporation from a row crop with incomplete cover. - Water resources research.

See Also

spwb

Examples

# NOT RUN {
SoilDepth = c(200,400,800,1200,1500)

#TOPSOIL LAYERS
d1 = pmin(SoilDepth, 300) #<300
#SUBSOIL LAYERS
d2 = pmax(0, pmin(SoilDepth-300,1200)) #300-1500 mm
#ROCK LAYER
d3 = 4000-(d1+d2) #From SoilDepth down to 4.0 m

TS_clay = 15
TS_sand = 25
SS_clay = 15
SS_sand = 25
RL_clay = 15
RL_sand = 25
TS_gravel = 20
SS_gravel = 40
RL_gravel = 95

Theta_FC1=soil.psi2thetaSX(TS_clay, TS_sand, -33) #in m3/m3
Theta_FC2=soil.psi2thetaSX(SS_clay, SS_sand, -33) #in m3/m3
Theta_FC3=soil.psi2thetaSX(RL_clay, RL_sand, -33) #in m3/m3
pcTS_gravel = 1-(TS_gravel/100)
pcSS_gravel = 1-(SS_gravel/100)
pcRL_gravel = 1-(RL_gravel/100)
MaxVol1 = (d1*Theta_FC1*pcTS_gravel)
MaxVol2 = (d2*Theta_FC2*pcSS_gravel)
MaxVol3 = (d3*Theta_FC3*pcRL_gravel)
V = MaxVol1+MaxVol2+MaxVol3

par(mar=c(5,5,1,1), mfrow=c(1,2))
NP = seq(0,60, by=1)
plot(NP,hydrology.soilInfiltration(NP, V[1]), type="l", xlim=c(0,60), ylim=c(0,60), 
     ylab="Infiltration (mm)", xlab="Net rainfall (mm)", frame=FALSE)
lines(NP,hydrology.soilInfiltration(NP, V[2]), lty=2)
lines(NP,hydrology.soilInfiltration(NP, V[3]), lty=3)
lines(NP,hydrology.soilInfiltration(NP, V[4]), lty=4)
lines(NP,hydrology.soilInfiltration(NP, V[5]), lty=5)
legend("topleft", bty="n", lty=1:5, 
       legend=c(paste("d =", SoilDepth, "Vsoil =",round(V),"mm")))
plot(NP,NP-hydrology.soilInfiltration(NP, V[1]), type="l", xlim=c(0,60), ylim=c(0,60), 
     ylab="Runoff (mm)", xlab="Net rainfall (mm)", frame=FALSE)
lines(NP,NP-hydrology.soilInfiltration(NP, V[2]), lty=2)
lines(NP,NP-hydrology.soilInfiltration(NP, V[3]), lty=3)
lines(NP,NP-hydrology.soilInfiltration(NP, V[4]), lty=4)
lines(NP,NP-hydrology.soilInfiltration(NP, V[5]), lty=5)
legend("topleft", bty="n", lty=1:5, 
       legend=c(paste("d =", SoilDepth,"Vsoil =",round(V),"mm")))


# }