fasstr (version 0.3.1)

plot_longterm_monthly_stats: Plot long-term summary statistics from annual monthly mean flows

Description

Plots the long-term monthly mean, median, maximum, minimum, and 5, 25, 75, and 95 percentiles of annual monthly mean flow values from a single streamflow dataset. Plots statistics from discharge values from all years, unless specified. The Maximum-Minimum band can be removed using the 'include_extremes' argument and the percentile bands can be customized using the 'inner_percentiles' and 'outer_percentiles' arguments. Data calculated using the calc_longterm_monthly_stats() function.

Usage

plot_longterm_monthly_stats(
  data,
  dates = Date,
  values = Value,
  groups = STATION_NUMBER,
  station_number,
  roll_days = 1,
  roll_align = "right",
  water_year_start = 1,
  start_year,
  end_year,
  exclude_years,
  complete_years = FALSE,
  ignore_missing = FALSE,
  include_extremes = TRUE,
  inner_percentiles = c(25, 75),
  outer_percentiles = c(5, 95),
  add_year,
  log_discharge = TRUE,
  include_title = FALSE
)

Arguments

data

A data frame of daily data that contains columns of dates, flow values, and (optional) groups (e.g. station numbers). Leave blank if using station_number argument.

dates

Column in data that contains dates formatted YYYY-MM-DD. Only required if dates column name is not ' Date' (default). Leave blank if using station_number argument.

values

Column in data that contains numeric flow values, in units of cubic metres per second. Only required if values column name is not 'Value' (default). Leave blank if using station_number argument.

groups

Column in data that contains unique identifiers for different data sets, if applicable. Only required if groups column name is not 'STATION_NUMBER'. Function will automatically group by a column named 'STATION_NUMBER' if present. Remove the 'STATION_NUMBER' column beforehand to remove this grouping. Leave blank if using station_number argument.

station_number

A character string vector of seven digit Water Survey of Canada station numbers (e.g. "08NM116") of which to extract daily streamflow data from a HYDAT database. Requires tidyhydat package and a HYDAT database. Leave blank if using data argument.

roll_days

Numeric value of the number of days to apply a rolling mean. Default 1.

roll_align

Character string identifying the direction of the rolling mean from the specified date, either by the first ('left'), last ('right), or middle ('center') day of the rolling n-day group of observations. Default 'right'.

water_year_start

Numeric value indicating the month of the start of the water year for analysis. Default 1.

start_year

Numeric value of the first year to consider for analysis. Leave blank to use the first year of the source data.

end_year

Numeric value of the last year to consider for analysis. Leave blank to use the last year of the source data.

exclude_years

Numeric vector of years to exclude from analysis. Leave blank to include all years.

complete_years

Logical values indicating whether to include only years with complete data in analysis. Default FALSE.

ignore_missing

Logical value indicating whether dates with missing values should be included in the calculation. If TRUE then a statistic will be calculated regardless of missing dates. If FALSE then only statistics from time periods with no missing dates will be returned. Default FALSE.

include_extremes

Logical value to indicate plotting a ribbon with the range of daily minimum and maximum flows. Default TRUE.

inner_percentiles

Numeric vector of two values of two percentiles indicating the lower and upper limits of the inner percentiles ribbon for plotting. Default c(25,75), set to NULL for no inner ribbon.

outer_percentiles

Numeric vector of two values of two percentiles indicating the lower and upper limits of the outer percentiles ribbon for plotting. Default c(5,95), set to NULL for no outer ribbon.

add_year

Numeric value indicating a year of daily flows to add to the daily statistics plot. Leave blank for no years.

log_discharge

Logical value to indicate plotting the discharge axis (Y-axis) on a logarithmic scale. Default FALSE.

include_title

Logical value to indicate adding the group/station number to the plot, if provided. Default FALSE.

Value

A list of ggplot2 objects with the following for each station provided:

Long-term_Monthly_Statistics

a plot that contains long-term flow statistics

Default plots on each object:

Monthly Mean

mean of all annual monthly means for a given month over all years

Monthly Median

median of all annual monthly means for a given month over all years

25-75 Percentiles Range

a ribbon showing the range of data between the monthly 25th and 75th percentiles

5-95 Percentiles Range

a ribbon showing the range of data between the monthly 5th and 95th percentiles

Max-Min Range

a ribbon showing the range of data between the monthly minimum and maximums

See Also

calc_longterm_monthly_stats

Examples

# NOT RUN {
# Run if HYDAT database has been downloaded (using tidyhydat::download_hydat())
if (file.exists(tidyhydat::hy_downloaded_db())) {

# Plot longterm monthly statistics using data argument with defaults
flow_data <- tidyhydat::hy_daily_flows(station_number = "08NM116")
plot_longterm_monthly_stats(data = flow_data,
                            start_year = 1980)

# Plot longterm monthly statistics using station_number argument with defaults
plot_longterm_monthly_stats(station_number = "08NM116",
                            start_year = 1980)
            
# Plot longterm monthly statistics and add a specific year's daily flows                
plot_longterm_monthly_stats(station_number = "08NM116",
                            start_year = 1980,
                            add_year = 1985) 
                              
                            
}
# }