lfstat (version 0.9.4)

recessionplot: Recession diagnostic plot

Description

Helps to define peaklevel of a lfobj and visualises recession periods.

Usage

recessionplot(lfobj, peaklevel = 0.95, plot = TRUE, peakreturn = FALSE, thresplot = TRUE, threscol = "blue", threshold = 70, thresbreaks = c("fixed","monthly","seasonal"), thresbreakdays = c("01/06","01/10"), recessionperiod = TRUE, recessioncol = "darkblue", seglength = 7, ...)

Arguments

lfobj

A object of class lfobj

peaklevel

A level between 0 and 1 or a logical vector, see details.

plot

Should a plot be made

peakreturn

Should a logical with rainpeaks be returned

thresplot

Should the threshold be plotted

threscol

Color of threshold in plot

threshold

Threshold level (70 refers to Q70)

thresbreaks

"fixed" uses a fixed threshold level, "monthly" calculates the threshold for every month separately, "seasonal" calculates thresholds for every season defined using "thresbreakdays".

thresbreakdays

Needed if "thresbreaks = 'seasonal'" to define the periodes for which separate thresholds should be calculated, see details

recessionperiod

Should recession periods be marked

recessioncol

Color of recessionperiod marks

seglength

The minimum number of days to be marked as recession period

...

Further arguments handed to hydrograph

Value

Details

For recession analysis it is necessary to define flood discharge peaks in the hydrograph. Peaklevel defines a day to be a discharge peak, if peaklevel * flow > flow[day before] and peaklevel * flow > flow[day after].

This function can be used to check different values of peaklevel.

References

Gustard, A. & Demuth, S. (2009) (Eds) Manual on Low-flow Estimation and Prediction. Operational Hydrology Report No. 50, WMO-No. 1029, 136p.

See Also

recession

Examples

## Not run: 
# data(ngaruroro)
# #To few points identified as peak flood discharge
# recessionplot(ngaruroro, peaklevel = .5, start = 1991, end = 1991)
# 
# #To many
# recessionplot(ngaruroro, peaklevel = .999, start = 1991, end = 1991)
# 
# #Good choice?
# recessionplot(ngaruroro, peaklevel = .92, start = 1991, end = 1991)
# 
# #Getting peakdays for 1991
# peak <- recessionplot(ngaruroro, peaklevel = .92, plot = FALSE)
# rain1991 <- subset(ngaruroro, subset = hyear == 1991 && peak, select = c(day, month, year))## End(Not run)