lfstat (version 0.9.4)

seglenplot: Barchart of recession length

Description

Plots a barchart to find a good value for 'seglength' when using recession.

Usage

seglenplot(lfobj, threslevel = 70, thresbreaks = c("fixed","monthly","seasonal"), thresbreakdays = NULL, rainpeaklevel = 0.95, na.rm = TRUE)

Arguments

lfobj

An object of class "lfobj"

threslevel

The threshold level (70 means Q70)

thresbreaks

"fixed" uses a fixed threshold level, "monthly" calculates the threshold for every month separatly, "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

rainpeaklevel

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

na.rm

Should NAs in the series be ignored?

Value

A barchart

Warning

Other then in the manual, we implemented a barchart instead of a histogram. To save space, empty bars are not plotted!

Details

For recession analysis it is necessary to define flood discharge peaks (rainpeaks) in the hydrograph. Rainpeaklevel defines a day to be a discharge peak, if rainpeaklevel * flow > flow[day before] and rainpeaklevel * flow > flow[day after]. If thresbreakdays or seasonbreakdays is a single day, e.g. "01/06", the start of the hydrological year is taken as the second breakday. If more than two seasons are to be specified, a vector of all breakdays is needed.

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)
# seglenplot(ngaruroro)## End(Not run)