R/calc_monthly_cumulative_stats.R
calc_monthly_cumulative_stats.RdCalculate cumulative monthly flow statistics for each month of the year of daily flow values from a daily streamflow
data set. Calculates statistics from all values from complete years, unless specified. Defaults to volumetric cumulative flows,
can use use_yield and basin_area to convert to area-based water yield. Returns a tibble with statistics.
calc_monthly_cumulative_stats(
data,
dates = Date,
values = Value,
groups = STATION_NUMBER,
station_number,
percentiles = c(5, 25, 75, 95),
use_yield = FALSE,
basin_area,
water_year_start = 1,
start_year,
end_year,
exclude_years,
months = 1:12,
transpose = FALSE
)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.
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.
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.
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.
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.
Numeric vector of percentiles to calculate. Set to NA if none required. Default c(5,25,75,95).
Logical value indicating whether to calculate area-based water yield, in mm, instead of volumetric discharge.
Default FALSE.
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.
Numeric value indicating the month (1 through 12) of the start of water year for
analysis. Default 1.
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.
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.
Numeric vector of years to exclude from analysis. Leave blank or set to NULL to include all years.
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.
Logical value indicating whether to transpose rows and columns of results. Default FALSE.
A tibble data frame with the following columns, default units in cubic metres, or millimetres if use_yield and basin_area provided:
month (MMM-DD) of cumulative statistics
monthly mean of all cumulative flows for a given month of the year
monthly mean of all cumulative flows for a given month of the year
monthly mean of all cumulative flows for a given month of the year
monthly mean of all cumulative flows for a given month of the year
each monthly n-th percentile selected of all cumulative flows for a given month of the year
Default percentile columns:
monthly 5th percentile of all cumulative flows for a given month of the year
monthly 25th percentile of all cumulative flows for a given month of the year
monthly 75th percentile of all cumulative flows for a given month of the year
monthly 95th percentile of all cumulative flows for a given month of the year
Transposing data creates a column of "Statistics" and subsequent columns for each year selected.
# Run if HYDAT database has been downloaded (using tidyhydat::download_hydat())
if (file.exists(tidyhydat::hy_downloaded_db())) {
# Calculate annual monthly cumulative volume statistics
calc_monthly_cumulative_stats(station_number = "08NM116")
# Calculate annual monthly cumulative volume statistics with default HYDAT basin area
calc_monthly_cumulative_stats(station_number = "08NM116",
use_yield = TRUE)
# Calculate annual monthly cumulative volume statistics with custom basin area
calc_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.
#> # A tibble: 12 × 10
#> STATION_NUM…¹ Month Mean Median Maximum Minimum P5 P25 P75 P95
#> <chr> <fct> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 08NM116 Jan 3.60 2.87 20.5 1.06 1.57 2.43 4.09 6.41
#> 2 08NM116 Feb 6.90 5.81 30.7 2.16 3.27 4.49 7.39 12.4
#> 3 08NM116 Mar 12.5 10.6 47.8 3.86 6.11 7.94 14.6 23.3
#> 4 08NM116 Apr 37.1 33.6 92.6 9.86 13.2 24.4 44.4 74.4
#> 5 08NM116 May 122. 114. 208. 52.3 66.1 94.1 142. 196.
#> 6 08NM116 Jun 195. 198. 319. 95.3 104. 148. 233. 289.
#> 7 08NM116 Jul 215. 222. 377. 102. 111. 158. 255. 332.
#> 8 08NM116 Aug 222. 226. 390. 104. 115. 162. 271. 339.
#> 9 08NM116 Sep 229. 234. 405. 106. 118. 165. 282. 345.
#> 10 08NM116 Oct 236. 241. 422. 108. 122. 170. 287. 351.
#> 11 08NM116 Nov 242. 244. 433. 110. 127. 176. 292. 358.
#> 12 08NM116 Dec 247. 247. 439. 112. 130. 180. 297. 361.
#> # … with abbreviated variable name ¹STATION_NUMBER