valiantzas: Valiantzas infiltration parameter optimization in R

In gowusu/vadose: The estimation of saturated hydraulic conductivity and soil water retention Curves in the vadose zone

Description

This function optimises Valiantzas (2010) cumulative infiltration (I) parameters: Ks, S and ratio between philip A and Ks.

Usage

valiantzas(data = NULL, time, I, S = 0.1, Ks = 0.3, type = "linear",
  ratio = 0.5, group = NULL)

## Default S3 method:
valiantzas(data = NULL, time, I, S = 0.1, Ks = 0.3,
  type = "linear", ratio = 0.5, group = NULL)

## S3 method for class 'valiantzas'
predict(object, time = NULL, ...)

## S3 method for class 'valiantzas'
plot(x, xlab = "Time(Minutes)",
  ylab = "Cumulative (mm)", main = NULL, layout = NULL, ...)

## S3 method for class 'valiantzas'
summary(object, ...)

## S3 method for class 'valiantzas'
print(x, ...)

## S3 method for class 'valiantzas'
coef(object, ...)

Arguments

data	dataframe. It can contain data with column names of "time" and "I"
time	character or numeric. The name of time variable in the dataframe. If the "data" parameter contains "time", this will be ignored. The unit must be in seconds.
I	cumulative infiltration (I) or infiltration rate (i) [mm]
S	numeric. sorptivity parameter
Ks	saturated hydraulic conductivity
type	character. It takes "linear" or "nonlinear" Philip equation
ratio	a parameter expressing relationship between philip A and Ks
group	character. The name of the group variables if the data is from different areas.
object	Model output object
...	Any other graphical parameter
x	a return object of the function.
xlab	x label of the plot
ylab	y label of the plot
main	Title of the plot
layout	plot layout

Value

• Ks: optimised saturated hydraulic conductivity

• S: optimised sorptivity [LT^-0.5]

• ratio: optimised ratio parameter

• output: output of the group simulation

Author(s)

George Owusu

References

Valiantzas, J. D. (2010). New linearized two-parameter infiltration equation for direct determination of conductivity and sorptivity. Journal of Hydrology, 387. doi: 10.1016/j.jhydrol.2009.12.049

Examples

data=read.csv(system.file("ext","sys","exampleBEST.csv",package="vadose"))
Valiantzas1<-valiantzas(data=data,time="time",I="I")
plot(Valiantzas1)
predict(Valiantzas1)
coef(Valiantzas1)


#infiltration rate
data=read.csv(system.file("ext","sys","infiltration2.csv",package="vadose"))
assin_breko<- subset(data, ID=="41A20_1")
Valiantzasr<-valiantzas(data=assin_breko,time="minutes",I="cm.hr")

#group simulation
Valiantzasg<-valiantzas(data=data,time="minutes",I="cm.hr",group="ID")
coef(Valiantzasg)
#generic function

gowusu/vadose documentation built on May 17, 2019, 7:59 a.m.