DWBmodelUN (version 1.0.0)

funFU: Fu's function for relationship between precipitation and potential evapotranspiration

Description

It is a model based on the postulates of Budyko, which stated that not only does the actual evapotranspiration depend on potential evapotranspiration, but it is also constrained by water availability (Budyko, 1974).

Usage

funFU(PET, P, alpha)

Arguments

PET

is the variable which will be inserted as the numerator in Fu's function. It can be a value or a numeric vector, in which case it must have the same length as the denominator vector.

P

is the variable which will be inserted as the numerator in Fu's function. It can be a value or a numeric vector, in which case it must have the same length as the numerator vector.

alpha

parameter of Fu's model which controls the evapotranspiration efficiency, yet it is named depending on the variables used as numerator and denominator. It must be a unique value of type double.

Value

a value or a vector (depending on which kind of data was introduced for numerator and denominator).

References

Zhang, L., Potter, N., Hickel, K., Zhang, Y., & Shao, Q. (2008). "Water balance modeling over variable time scales based on the Budyko framework <U+2013> Model development and testing. Journal of Hydrology", 360(1-4), 117<U+2013>131.

Budyko. (1974). "Climate and life". New York: Academic Press, INC.

Examples

# NOT RUN {
PET <- 1000
P <- 2000
alpha <- 0.69  # value used by Zhang et al. (2008) 
funFU(PET, P, alpha)

# }