ms_calc_flux: Calculate daily solute fluxes

In MacroSHEDS/macrosheds: Tools for interfacing with the MacroSheds dataset

Calculate daily solute fluxes

Description

Determines solute fluxes from interpolated daily Q (discharge or precipitation) and corresponding chemistry data. For cumulative solute loads computed by various methods, see ms_calc_load().

Usage

ms_calc_flux(chemistry, q)

Arguments

chemistry	A data.frame of precipitation or stream chemistry data in MacroSheds format (see details) and in units of mg/L.
q	A data.frame in MacroSheds format (see details) containing stream discharge in L/s or precipitation in mm.

Details

#' MacroSheds format (only date, site_code, var, and val are required in inputs to this function):

column	definition
date	Date in YYYY-mm-dd
site_code	A unique identifier for each MacroSheds site, identical to primary source site code where possible. See ms_load_sites().
grab_sample	Boolean integer indicating whether the observation was obtained via grab sample or installed sensor. 1 = TRUE (grab sample), 0 = FALSE (installed sensor).
var	Variable code. See ms_load_variables().
val	Data value. See ms_load_variables() for units.
ms_status	Boolean integer. 0 = clean value. 1 = questionable value. See "Technical Validation" section of the MacroSheds data paper for details.
ms_interp	Boolean integer. 0 = measured or imputed by primary source. 1 = interpolated by MacroSheds. See "Temporal Imputation and Aggregation" section of the MacroSheds data paper for details.
val_err	The combined standard uncertainty associated with the corresponding data point, if estimable. See "Detection Limits and Propagation of Uncertainty" section of the MacroSheds data paper for details.

This is the format returned by ms_load_product for core time-series data.

Our Solute fluxes are calculated by multiplying solute concentration by daily water volume. Stream and precipitation flux are computed differently. For stream flux (stream chemistry * discharge), flux is: kg/ha/d = mg/L \* L/s \* 86400 / 1e6 / ws_area. Precipitation flux (precip chemistry \* precip depth over the watershed) is calculated as: kg/ha/d = mg/L \* mm/d / 100. You can convert between kg/ha/d and kg/d using ms_scale_flux_by_area() and ms_undo_scale_flux_by_area().

Value

returns a tibble in MacroSheds format (see details) of stream or precipitation chemical flux for every dayduring which discharge/precipitation and chemistry are reported. Output units are kg/ha/d.

Author(s)

Spencer Rhea

Mike Vlah, [e-mail]

Wes Slaughter

See Also

ms_calc_load(), ms_scale_flux_by_area(), ms_undo_scale_flux_by_area()

Examples

ms_root = 'data/macrosheds'
ms_download_core_data(macrosheds_root = ms_root,
                      domains = 'hbef')

chemistry <- ms_load_product(macrosheds_root = ms_root,
                             prodname = 'stream_chemistry',
                             site_codes = c('w1', 'w3'),
                             filter_vars = c('NO3_N', 'Cl'))

q <- ms_load_product(macrosheds_root = ms_root,
                     prodname = 'discharge',
                     site_codes = c('w1', 'w3'))

flux <- ms_calc_flux(chemistry = chemistry,
                     q = q)

MacroSHEDS/macrosheds documentation built on Oct. 30, 2024, 11:15 a.m.