IDFcurves: Obtain Intensity-Duration-Frequency curves

Description

Intensity-Duration-Frequency curves are obtained from a sub-hourly time series of precipitation by adjusting Generalized Extreme Value distribution to annual maxima of different time intervals.

Usage

IDFcurves(prdat, stname, clmn=1:2, tz='utc', na.code=NA,
prunits='mm', mindpy=0.8, gumbel=TRUE, timeaggr=c(10,20,30,60,120,180,360,720),
retper=c(5,10,20,30,50,75,100),...)

Value

A table of maximum precipitation accumulations (totals, not mm/h as in the graphic) is returned invisibly.

Arguments

prdat: Data frame with Time (as POSIXct) and sub-hourly precipitation data.
stname: Station name.
clmn: Columns where Time and precipitation data are located in prdat.
tz: Time zone ['utc' by default].
na.code: Numeric missing data code.
prunits: Precipitation units [mm].
mindpy: Minimum available data proportion to process data in any year.
gumbel: Adjust a Gumbel distribution? [TRUE].
timeaggr: Time intervals (in minutes) on which to aggregate precipitation.
retper: Return periods (in years) for extreme precipitation estimation.
...: Additional graphic parameters.

Details

The precipitation time series must be provided as a data frame with POSIXct times in the first column and precipitation in the second. However, these data can be in other columns of a wider data frame if the columns containing these variables are defined in the parameter clmn.

When setting gumbel=FALSE a Generalized Extreme Value distribution will be adjusted instead of the particular case of a Gumbel distribution.

Examples

Run this code

if (FALSE) {
data(climatol_data)
tab <- IDFcurves(prec10min,'My airport',cex.axis=1.2,cex.lab=1.2) #IDF plot

## See the maximum precipitation accumulations in the different time intervals:
tab
}