FlowScreen (version 2.0)

pk.bf.stats: Calculate baseflow peak statistics

Description

This function finds the start, middle, end, and duration of the baseflow peak based on percent of the total annual baseflow volume. A value of 0 is returned for years with no flow. Hydrologic years with fewer than normal observations (outliers) are excluded from the analysis, and for stations with seasonal flow records, additional seasonal subsetting is done to include only days with observations in all years.

Usage

pk.bf.stats(TS, bfpct = c(25, 50, 75))

Value

Returns a data.frame with the following columns:

• Start - day of year defining the start of the baseflow peak

• Mid - day of year defining the middle of the baseflow peak

• End - day of year defining the end of the baseflow peak

• Dur - duration of the baseflow peak, in days

Arguments

TS

data.frame of streamflow time series loaded with read.flows.

bfpct

numeric vector of percentages used to define the start, middle, and end of the baseflow peak. Default is c(25, 50, 75)

Author

Jennifer Dierauer

Details

This function calculates metrics intended to focus on snowmelt-related streamflow occuring in spring and summer. For catchments in cold climates, the baseflow peak can be interpreted as snowmelt-induced. Baseflow is estimated with bf_eckhardt. If total annual flow is equal to 0, returns NA for that year.

Examples

data(caniapiscau)
cania.ts <- create.ts(caniapiscau, hyrstart = 4)
cania.ts <- drop.years(cania.ts)
cania.ts <- set.plot.titles(cania.ts, 
title.elements = c("StationID", "StnName", "StateProv"))
res1 <- pk.bf.stats(cania.ts)

# trend and changepoint plot for baseflow peak start doy
res2 <- screen.metric(res1[,1], ylabel = "Day of Year")