Plot cumulative monthly flow statistics

Plot the monthly cumulative mean, median, maximum, minimum, and 5, 25, 75, 95th percentiles for each month of the year from a daily streamflow data set. Calculates statistics from all values from complete years, unless specified. Data calculated using calc_monthly_cumulative_stats() function. Can plot individual years for comparison using the add_year argument. Defaults to volumetric cumulative flows, can use use_yield and basin_area to convert to water yield. Returns a list of plots.

plot_monthly_cumulative_stats(
  data,
  dates = Date,
  values = Value,
  groups = STATION_NUMBER,
  station_number,
  use_yield = FALSE,
  basin_area,
  water_year_start = 1,
  start_year,
  end_year,
  exclude_years,
  months = 1:12,
  log_discharge = FALSE,
  log_ticks = ifelse(log_discharge, TRUE, FALSE),
  include_title = FALSE,
  add_year
)

Arguments

data

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

dates

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

values

Name of 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

Name of 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

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.

use_yield

Logical value indicating whether to calculate area-based water yield, in mm, instead of volumetric discharge. Default FALSE.

basin_area

Upstream drainage basin area, in square kilometres, to apply to observations. Three options:

(1) Leave blank if groups is STATION_NUMBER with HYDAT station numbers to extract basin areas from HYDAT.

(2) A single numeric value to apply to all observations.

(3) List each basin area for each group/station in groups (can override HYDAT value if listed) as such c("08NM116" = 795, "08NM242" = 10). If group is not listed the HYDAT area will be applied if it exists, otherwise it will be NA.

water_year_start

Numeric value indicating the month (1 through 12) of the start of water year for analysis. Default 1.

start_year

Numeric value of the first year to consider for analysis. Leave blank or set well before start date (i.e. 1800) to use from the first year of the source data.

end_year

Numeric value of the last year to consider for analysis. Leave blank or set well after end date (i.e. 2100) to use up to the last year of the source data.

exclude_years

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

months

Numeric vector of months to include in analysis. For example, 3 for March, 6:8 for Jun-Aug or c(10:12,1) for first four months (Oct-Jan) when water_year_start = 10 (Oct). Default summarizes all months (1:12). Need to be consecutive months for given year/water year to work properly.

log_discharge

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

log_ticks

Logical value to indicate plotting logarithmic scale ticks when log_discharge = TRUE. Ticks will not appear when log_discharge = FALSE. Default to TRUE when log_discharge = TRUE.

include_title

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

add_year

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

Value

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

Monthly_Cumulative_Stats: a plot that contains monthly cumulative flow statistics

Default plots on each object:

Mean: monthly cumulative mean
Median: monthly cumulative median
Min-5 Percentile Range: a ribbon showing the range of data between the monthly cumulative minimum and 5th percentile
5-25 Percentiles Range: a ribbon showing the range of data between the monthly cumulative 5th and 25th percentiles
25-75 Percentiles Range: a ribbon showing the range of data between the monthly cumulative 25th and 75th percentiles
75-95 Percentiles Range: a ribbon showing the range of data between the monthly cumulative 75th and 95th percentiles
95 Percentile-Max Range: a ribbon showing the range of data between the monthly cumulative 95th percentile and the maximum
'Year' Flows: (optional) the monthly cumulative flows for the designated year

Examples

# Run if HYDAT database has been downloaded (using tidyhydat::download_hydat())
if (file.exists(tidyhydat::hy_downloaded_db())) {

# Plot annual cumulative volume statistics
plot_monthly_cumulative_stats(station_number = "08NM116") 

# Plot annual cumulative yield statistics with default HYDAT basin area
plot_monthly_cumulative_stats(station_number = "08NM116",
                              use_yield = TRUE) 

# Plot annual cumulative yield statistics with custom basin area
plot_monthly_cumulative_stats(station_number = "08NM116",
                              use_yield = TRUE,
                              basin_area = 800) 
                              
}
#> Warning: One or more years contained partial data and were excluded. Only years with complete data were used for calculations.
#> Warning: One or more years contained partial data and were excluded. Only years with complete data were used for calculations.
#> Warning: One or more years contained partial data and were excluded. Only years with complete data were used for calculations.
#> $Monthly_Cumulative_Yield_Stats

#>

Arguments

Value

See also

Examples