S-SEBI Evapotranspiration Fraction

ssebi computes Roerink et. al (2000) S-SEBI: A simple remote sensing algorithm to estimate the surface energy balance.

Usage

ssebi(
  Ts,
  albedo = NULL,
  threshold = 0.2,
  plot = TRUE,
  Rn24 = NULL,
  folder = NULL,
  welev = NULL
)

# Default S3 method
ssebi(
  Ts = NULL,
  albedo = NULL,
  threshold = 0.2,
  plot = TRUE,
  Rn24 = NULL,
  folder = NULL,
  welev = NULL
)

Arguments

Ts: A RasterLayer data that indicates radiometric surface temperature values from remote sensing image, preferably in Kelvin (K). You can also point to raster file on your computer.
albedo: A RasterLayer data that has albedo values. You can also provide file path or location on your computer
threshold: numeric. Albedo inflection point threshold
plot: logical:TRUE or FALSE. To indicate if histograms or triangle should be plotted
Rn24: A 24 hour net radiation [W/m2]. It is needed to estimate daily ET. It can be computed with ETo with even a minimal data of Tmax and Tmin. You can also point to raster file on your computer
folder: An original directory of the images that contains all landsat 5,7 or 8 bands and metadata. At the moment only Landsat folder is supported
welev: Weather station elevation in meters

Value

EF, amax,bmax,amin,bmin

References

Roerink, G. J., Su, Z., & Menenti, M. 2000. S-SEBI: A simple remote sensing algorithm to estimate the surface energy balance. Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere , 25(2): 147-157.

Author

George Owusu

Examples

if (FALSE) { # \dontrun{
#Manual data specification
albedo=raster(system.file("extdata","albedo.grd",package="sebkc"))
Ts=raster(system.file("extdata","Ts.grd",package="sebkc"))
mod=ssebi(Ts=Ts,albedo=albedo,threshold=0,plot=TRUE)

#Using landsat folder
folder=system.file("extdata","stack",package="sebkc")
ssebiauto=ssebi(folder=folder,welev=278)
} # }