ndvilst.plot: Plot the NDVI-LST plot for estimation of Tmax and Tmin for...

In DGampe/TriangleMethod: Calculation of NDVI, LST and finally provide an estimation for actual evapotranspiration patterns using remote sensing data (default LANDSAT TM and ETM+ scenes).

Plot the NDVI-LST plot for estimation of Tmax and Tmin for further processing the triangle method.

Description

The Priestley Taylor coefficient PHI is scaled through the triangle shaped plot created from NDVI and LST. This function creates this type of plot, allows manual fitting and finally the more precise estimation of Tmin and Tmax for the estimation of actual evapotranspiration with the triangle method. The resulting plot combines the original NDVI-LST plot which can be found in Jiang & Islam (1999) with some modifications (e.g. adding the true dry edge) inspired by Stisen et al. (2008). However, the liniar relationship proposed by Jiang & Islam is kept here.

Usage

  ndvilst.plot(NDVI, LST, ...)

Arguments

NDVI	Can either be the filename of the raster containing the NDVI-information, or the allready raster variable in the workspace.
LST	Can either be the filename of the raster containing the LST/Ts-information, or the allready raster variable in the workspace.
write	specify, if the plot output should be writte to file. Default: T (alternative input F)
Tmin	Tmin from NDVI-LST plot. Lower end of vegetation cluster in plot. Default: c() (will be calculated)
Tmax	Tmax from NDVI-LST plot. Maximum temperature for vegetation cluster in plot. Default: c() (will be calculated)c()
outpath	Path to write the resulting plot file, if write =T. Default is current working directory.
outname	Name of the resulting .png file containg the plot. Default: c() (will be named automatically.)
plot.unit	Unit of the y-axis (LST). Default is depended on values of LST and will change automatically. Possible values are 'C' or 'K'.
classify	Should NDVI be classified (classes of 0.05 -steps) ? Default = T
plot.ylim	Limit of the y - axis.
plot.xlim	Limit of the x - axis.
plot.main	Title for the plot. Default: 'NDVI-LST-plot'
plot.xlab	Label for x-axis. Default: 'NDVI'
plot.ylab	Label for y-axis. Default: LST deg C / LST K, dependend on scale of input LST.
plot.wetcol	Color for line wet edge. Default: 'blue'
plot.drycol	Color for observed dry edge. Default: 'red'
plot.ndvi0	Color for NDVI = 0 vertical line. Default: 'forestgreen'
textwet.x	X position for label of the wet edge.
textwet.lab	Label for wet edge line. Default: 'wet edge'
textwet.col	Color for wet edge line. Default: 'blue'
textwet.font	Font for wet edge line. Default: 2
textwet.cex	Siye of text. Default 0.9
textobs.x	X position for observed dry edge.
textobs.lab	see textwet. Default: 'observed dry edge'
textobs.col	see textwet. Default: 'red'
textobs.font	see textwet. Default: 2
textobs.cex	see textwet. Default: 0.9
textdry.x	X position for label of the true dry edge.
textdry.lab	see textwet. Default: 'true dry edge'
textdry.col	see textwet. Default: 'black'
textdry.font	see textwet. Default: 2
textdry.cex	see textwet. Default: 0.9
textwater.x	X position for label of the water-pixels
textwater.lab	see textwet. Default: 'water'
textwater.col	see textwet. Default: 'black'
textwater.font	see textwet. Default: 2
textwater.cex	see textwet. Default: 0.9
textndvi.x	X position for label of NDVI = 0.
textndvi.lab	see textwet.
textndvi.col	see textwet.
textndvi.font	see textwet.
textndvi.cex	see textwet.
arrow.x0	x 0 for arrow. see ?arrows for details
arrow.y0	y 0 for arrow. see ?arrows for details
arrow.x1	x 1 for arrow. see ?arrows for details
arrow.angle	Angle for arrow. see ?arrows for details
arrow.code	Default 2. see ?arrows for details
arrow.length	Default 0.15 see ?arrows for details
arrow.lwd	Lwd for arrow. Default 2. see ?arrows for details
arrow.col	Color for arrow. Default 'black'. see ?arrows for details
pointmin.x	X position for point for PHI-min.
pointmin.col	Color for point for PHI-min. Default: 'black'
pointmin.type	Type for point for PHI-min. Default: 'p'
pointmin.lwd	Lwd for point for PHI-min.
pointmin.pch	Symbol for point for PHI-min. Default: 16
textmin.x	X position for label of PHI-min.
textmin.lab	Label for label of PHI-min.
textmin.col	Color for lable for label of PHI-min.
textmin.font	Font for for label of PHI-min.
textmin.cex	Size of label of PHI-min.
pointmax.x	X position for point for PHI-max.
pointmax.col	see pointmin.
pointmax.type	see pointmin.
pointmax.lwd	see pointmin.
pointmax.pch	see pointmin.
textmax.x	see textmin
textmax.lab	see textmin
textmax.col	see textmin
textmax.font	see textmin
textmax.cex	see textmin
textwet.y	Y-position for textwet. Default will be determined by the function.
textobs.y	Y-position for textobs. Default will be determined by the function.
textdry.y	Y-position for textdry. Default will be determined by the function.
textndvi.y	Y-position for textndvi. Default will be determined by the function.
textwater.y	Y-position for textwater. Default will be determined by the function.
arrow.y1	Y-position for arrow y 1. Default will be determined by the function.
pointmin.y	Y-position for pointmin. Default will be determined by the function.
textmin.y	Y-position for textmin. Default will be determined by the function.
pointmax.y	Y-position for pointmax y. Default will be determined by the function.
textmax.y	Y-position for textmax. Default will be determined by the function.
n.highest	The nth highest temperature to automatically define the dry edge temperature. Default is n.highest = 2. Numeric.
...	Plot is based on smoothScatter function. Additional arguments can be passed.

References

Jiang and Islam (1999): A methodology for estimation of surface evapotranspiration over large areas using remote sensing observatios

Batra et al. (2006): Estimation and comparison of evapotranspiration from MODIS and AVHRR sensors for clear sky days over the Southern Great Plains, Remote Sensing of the Environment, 103, 1-15

Stisen et al. (2008): Combining the triangle method with thermal inertia to estimate regional evapotranspiration - Applied to MSG-SEVIRI data in the Senegal River basin, Remote Sensing of the Environment, 112, 1242-1255

Wang et al. (2006): Estimation of evaporative fraction from a combination of day and night land surface temperatures and NDVI: A new method to determine the Priestley-Taylor parameter, Remote Sensing of the Environment, 102, 293-305

See Also

smoothScatter ndvi lsttm lstetm

Examples

  # ndvilst.plot('Your-NDVI-File-Here','Your-LST-File-Here')
  ndvi <- raster(ncol=30,nrow=20)
  ndvi [] <- runif(30*20,min = -1,max = 1)
  lst <- raster(ncol=30,nrow=20)
  lst [] <- runif(30*20,min = 15,max = 35)
  ndvilst.plot(ndvi,lst,write = FALSE)

DGampe/TriangleMethod documentation built on March 18, 2022, 6:43 a.m.