add_basin_area {fasstr}

Add a basin area column to daily flows

Description

Add a column of basin areas to a daily streamflow data set, in units of square kilometres.

Usage

add_basin_area(data, groups = STATION_NUMBER, station_number, basin_area)

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.

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.

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.

Value

A tibble data frame of the original source data with an additional column:

Basin_Area_sqkm

area of upstream drainage basin area, in square kilometres

Examples

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

# Add the HYDAT basin area to a data frame with station numbers
flow_data <- tidyhydat::hy_daily_flows(station_number = "08NM116")
add_basin_area(data = flow_data)

# Add the HYDAT basin area to data from HYDAT
add_basin_area(station_number = "08NM116")

# Set a custom basin area
add_basin_area(station_number = "08NM116",
               basin_area = 800)
               
# Set multiple custom basin areas for multiple stations
add_basin_area(station_number = c("08NM116", "08NM242"),
               basin_area = c("08NM116" = 800, "08NM242" = 10))

}