fdcu: Flow Duration Curve with uncertainty bounds.

In hydroTSM: Time Series Management and Analysis for Hydrological Modelling

Flow Duration Curve with uncertainty bounds.

Description

Computes and plots the Flow Duration Curve (FDC) for the streamflows given by x and for two uncertainty bounds, with the possibility of plotting an additional FDC representing simulated streamflows for x, in order to compare them.

Usage

fdcu(x, lband, uband, ...)

## Default S3 method:
fdcu(x, lband, uband, sim=NULL, lQ.thr=0.7, hQ.thr=0.2, plot=TRUE, log="y", 
     main="Flow Duration Curve", xlab="% Time flow equalled or exceeded", 
     ylab="Q, [m3/s]", ylim, yat=c(0.01, 0.1, 1), xat=c(0.01, 0.025, 0.05), 
     col=c("black", "red"), pch=c(1, 15), lwd=c(1, 0.8), lty=c(1, 3), cex=0.2, 
     cex.axis=1.2, cex.lab=1.2, leg.txt= c("Qobs", "Qsim", "95PPU"), 
     leg.cex=1, leg.pos="auto", verbose= TRUE, thr.shw=TRUE, border=NA, 
     bands.col="lightcyan", bands.density=NULL, bands.angle=45, new=TRUE, ...)

## S3 method for class 'matrix'
fdcu(x, lband, uband, sim=NULL, lQ.thr=0.7, hQ.thr=0.2, plot=TRUE, log="y", 
     main="Flow Duration Curve", xlab="% Time flow equalled or exceeded", 
     ylab="Q, [m3/s]", ylim, yat=c(0.01, 0.1, 1), xat=c(0.01, 0.025, 0.05), 
     col=matrix(c(rep("black", ncol(x)), 
     palette("default")[2:(ncol(x)+1)]), byrow=FALSE, ncol=2), 
     pch=matrix(rep(c(1, 15), ncol(x)), byrow=TRUE, ncol=2),
     lwd=matrix(rep(c(1, 0.8), ncol(x)), byrow=TRUE, ncol=2),
     lty=matrix(rep(c(1, 3), ncol(x)), byrow=TRUE, ncol=2),                        
     cex=rep(0.1, ncol(x)), cex.axis=1.2, cex.lab=1.2, 
     leg.txt=c("OBS", colnames(x), "95PPU"),  leg.cex=1, leg.pos="auto", 
     verbose= TRUE,  thr.shw=TRUE, border=rep(NA, ncol(x)), 
     bands.col=rep("lightcyan", ncol(x)), bands.density=rep(NULL, ncol(x)), 
     bands.angle=rep(45, ncol(x)), new=TRUE, ...)

## S3 method for class 'data.frame'
fdcu(x, lband, uband, sim=NULL, lQ.thr=0.7, hQ.thr=0.2, plot=TRUE, log="y", 
     main="Flow Duration Curve", xlab="% Time flow equalled or exceeded", 
     ylab="Q, [m3/s]", ylim, yat=c(0.01, 0.1, 1), xat=c(0.01, 0.025, 0.05), 
     col=matrix(c(rep("black", ncol(x)), 
     palette("default")[2:(ncol(x)+1)]), byrow=FALSE, ncol=2),
     pch=matrix(rep(c(1, 15), ncol(x)), byrow=TRUE, ncol=2),
     lwd=matrix(rep(c(1, 0.8), ncol(x)), byrow=TRUE, ncol=2),
     lty=matrix(rep(c(1, 3), ncol(x)), byrow=TRUE, ncol=2),                        
     cex=rep(0.1, ncol(x)), cex.axis=1.2, cex.lab=1.2,
     leg.txt=c("OBS", colnames(x), "95PPU"), leg.cex=1, leg.pos="auto", 
     verbose= TRUE, thr.shw=TRUE, border=rep(NA, ncol(x)), 
     bands.col=rep("lightcyan", ncol(x)), bands.density=rep(NULL, ncol(x)), 
     bands.angle=rep(45, ncol(x)), new=TRUE, ...)

Arguments

x	numeric, zoo, data.frame or matrix object with the observed streamflows for which the flow duration curve have to be computed. Measurements at several gauging stations can be stored in a data.frame of matrix object, and in that case, each column of x represent the time series measured in each gauging station, and the column names of x have to correspond to the ID of each station (starting by a letter). When x is a matrix or data.frame, the flow duration curve is computed for each column.
lband	numeric, zoo, data.frame or matrix object with the streamflows representing the the lower uncertainty bound of x, for which the flow duration curve have to be computed. Measurements at several gauging stations can be stored in a data.frame of matrix object. When lband is a matrix or data.frame, the flow duration curve is computed for each column.
uband	numeric, zoo, data.frame or matrix object with the streamflows representing the the upper uncertainty bound of x, for which the flow duration curve have to be computed. Measurements at several gauging stations can be stored in a data.frame of matrix object. When uband is a matrix or data.frame, the flow duration curve is computed for each column.
sim	OPTIONAL. numeric, zoo, data.frame or matrix object with the streamflows simulated for x, for which the flow duration curve have to be computed. Measurements at several gauging stations can be stored in a data.frame of matrix object. When sim is a matrix or data.frame, the flow duration curve is computed for each column.
lQ.thr	numeric, low flows separation threshold. If this value is different from 'NA', a vertical line is drawn in this value, and all the values to the left of it are deemed low flows.
hQ.thr	numeric, high flows separation threshold. If this value is different from 'NA', a vertical line is drawn in this value, and all the values to the right of it are deemed high flows
plot	logical. Indicates if the flow duration curve should be plotted or not.
log	character, indicates which axis has to be plotted with a logarithmic scale. Default value is y.
main	See plot. An overall title for the plot: see title.
xlab	See plot. A title for the x axis: see title.
ylab	See plot. A title for the y axis: see title.
ylim	See plot.default. The y limits of the plot.
yat	Only used when log="y". numeric, with points at which tick-marks will try to be drawn in the Y axis, in addition to the defaults computed by R. See the at argument in Axis.
xat	Only used when log="x". numeric, with points at which tick-marks will try to be drawn in the x axis, in addition to the defaults computed by R. See the at argument in Axis.
col	See plot.default. The colors for lines and points. Multiple colors can be specified so that each point can be given its own color. If there are fewer colors than points they are recycled in the standard fashion. Lines will all be plotted in the first colour specified.
pch	See plot.default. A vector of plotting characters or symbols: see points.
lwd	See plot.default. The line width, see par.
lty	See plot.default. The line type, see par.
cex	See plot.default. A numerical vector giving the amount by which plotting characters and symbols should be scaled relative to the default. This works as a multiple of par("cex"). 'NULL' and 'NA' are equivalent to '1.0'. Note that this does not affect annotation.
cex.axis	magnification of axis annotation relative to 'cex'.
cex.lab	Magnification to be used for x and y labels relative to the current setting of 'cex'. See '?par'.
leg.txt	vector with the names that have to be used for each column of x.
leg.cex	numeric, indicating the character expansion factor for the legend, *relative* to current par("cex"). Default value = 1
leg.pos	keyword to be used to position the legend. One of the list ‘"bottomright", "bottom", "bottomleft", "left", "topleft", "top", "topright", "right", "center"’. This places the legend on the inside of the plot frame at the given location. See legend. When leg.pos="auto", the legend provided by leg.txt is located on the ‘bottomleft’ when log="y" and on the ‘topright’ otherwise
verbose	logical; if TRUE, progress messages are printed
thr.shw	logical, indicating if the streamflow values corresponding to the user-defined thresholds lQ.thr and hQ.thr have to be shown in the plot. When leg.pos="auto", the legend with the threshold values is located on the ‘topright’ when log="y" and on the ‘bottomleft’ otherwise
border	See polygon. The color to draw the border of the polygon with the uncertainty bounds. The default, 'NA', means to omit borders.
bands.col	See polygon. The color for filling the polygon. The default, 'NA', is to leave polygons unfilled, unless bands.density is specified. If bands.density is specified with a positive value this gives the color of the shading lines.
bands.density	See polygon. The density of shading lines for the polygon with the uncertainty bounds, in lines per inch. The default value of 'NULL' means that no shading lines are drawn. A zero value of bands.density means no shading nor filling whereas negative values (and 'NA') suppress shading (and so allow color filling).
bands.angle	See polygon. The slope of shading lines for the polygon with the uncertainty bounds, given as an angle in degrees (counter-clockwise).
new	logical, if TRUE, a new plotting window is created.
...	further arguments passed to or from other methods (to the plotting functions)

Note

If you do not want to use logarithmic scale for the streamflow axis, you can do it by passing the log=" " to the ... argument.

Author(s)

Mauricio Zambrano-Bigiarini, mzb.devel@gmail

References

Vogel, R., and N. M. Fennessey (1994), Flow duration curves I: A new interpretation and confidence intervals, ASCE, Journal of Water Resources Planning and Management, 120(4).

Vogel, R., and N. Fennessey (1995), Flow duration curves II: A review of applications in water resources planning, Water Resources Bulletin, 31(6), 1029-1039, doi:10.1111/j.1752-1688.1995.tb03419.x.

Yilmaz, K. K., H. V. Gupta, and T. Wagener (2008), A process-based diagnostic approach to model evaluation: Application to the NWS distributed hydrologic model, Water Resour. Res., 44, W09417, doi:10.1029/2007WR006716.

See Also

fdc

Examples

## Loading daily streamflows at the station Oca en Ona (Ebro River basin, Spain) ##
data(OcaEnOnaQts)
q <- OcaEnOnaQts

# Creating a fictitious lower uncertainty band
lband <- q - min(q, na.rm=TRUE)

# Giving a fictitious upper uncertainty band
uband <- q + mean(q, na.rm=TRUE)

# Plotting the flow duration curve corresponding to 'q', with two uncertainty bounds
fdcu(q, lband, uband)

hydroTSM documentation built on Nov. 4, 2024, 5:07 p.m.