Computes several values of the flow duration curve for streamflow centered on a specific date of the year
Source:R/flowDuration.R
flowDuration.RdThis function is useful for helping the analyst determine the empirical probability distribution of streamflow for a particular part of the year or for the whole year. This is particularly useful in setting up discharge scales for various other plots in this package.
Arguments
- eList
named list with at least Daily and INFO dataframes
- centerDate
character specifying the center date of the part of the year for which the flow duration is to be calculated, it is in the form "mm-dd" (it must be in quotes). Default is "09-30"
- qUnit
object of qUnit class
printqUnitCheatSheet, or numeric represented the short code, or character representing the descriptive name. Default is qUnit = 2, which corresponds to cubic meters per second.- span
number this is the half-width of the window over which the discharge values are to be used in constructing the flow-duration curve. If the full year is desired any value greater than 182 will. Note that for a window of about 2-months width, a span value should be about 30. Default is 365.
- monthLab
object of monthLabel class, or numeric represented the short code, or character representing the descriptive name.
Examples
eList <- Choptank_eList
# for a window of 30 days either side of June 25 expressed in units
# of cfs:
flowDuration(eList, "06-25", qUnit = 1, span = 30)
#>
#> Flow Duration for Choptank River
#>
#> Flow duration period is centered on June 25
#> And spans the period from May 26 To July 25
#>
#> Discharge units are Cubic Feet per Second
#> min 5% 10% 25% 50% 75% 90% 95% max
#> 3.6 13.0 16.0 30.0 52.0 100.0 213.0 335.0 3830.0
# for a flow-duration curve covering the whole year,
# expressed in units of cms, and returning a data frame of results:
qDuration <- flowDuration(eList, qUnit = 2)
#>
#> Flow Duration for Choptank River
#>
#> Flow duration is based on full year
#>
#> Discharge units are Cubic Meters per Second