independentEvents {discharge}

Independent high- or low-flow events

Description

Finds independent events greater than or less than a specified criterion. High (or low) -flow days occurring on consecutive days are considered part of one event. This function can be used to find events exceeding 2- or 10- year return levels (as calculated in lp3Events function, for example), or to find residual flows of a certain magnitude.

Usage

independentEvents(cutoff.val, data, data.column, below.cutoff=FALSE)

Arguments

cutoff.val

Numeric specifying event criterion.

data

Data matrix or data frame with one column of streamflow data.

data.column

Numeric; specifies column in which to look for events.

below.cutoff

Logical. TRUE to find events less than the cutoff.val and FALSE to find events greater than the cutoff.val.

Value

A data.frame with columns

events.starts

Index of event start.

events.ends

Index of event end.

events.duration

Length (days) of event.

extreme.this.events

Maximum or minimum flow for this event.

ind.extreme

Index of maximum or minimum flow for this event. If extreme is not unique, the chronologically first index is given.

...

All columns of original data, corresponding to max or min flow. These columns will have the same column names as the original data.

duplicates

0 if the extreme is unique, 1 if it is not unique.

See Also

lp3Events

Examples

data(sycamore)
syc.sf<-asStreamflow(sycamore)
#find 10-year flood
q10<-lp3Events(syc.sf)$Q10

#find all events greater than 10-year flood
independentEvents(q10,syc.sf$data, data.col=8 , below.cutoff=FALSE)