define_water function

Create a water class object given water quality parameters

This function takes user-defined water quality parameters and creates an S4 "water" class object that forms the input and output of all tidywater models.

define_water(
  ph,
  temp = 25,
  alk,
  tot_hard,
  ca,
  mg,
  na,
  k,
  cl,
  so4,
  free_chlorine = 0,
  combined_chlorine = 0,
  tot_po4 = 0,
  tot_nh3 = 0,
  tds,
  cond,
  toc,
  doc,
  uv254,
  br,
  f,
  fe,
  al,
  mn
)

Arguments

• ph: water pH
• temp: Temperature in degree C
• alk: Alkalinity in mg/L as CaCO3
• tot_hard: Total hardness in mg/L as CaCO3
• ca: Calcium in mg/L Ca2+
• mg: Magnesium in mg/L Mg2+
• na: Sodium in mg/L Na+
• k: Potassium in mg/L K+
• cl: Chloride in mg/L Cl-
• so4: Sulfate in mg/L SO42-
• free_chlorine: Free chlorine in mg/L as Cl2. Used when a starting water has a free chlorine residual.
• combined_chlorine: Combined chlorine (chloramines) in mg/L as Cl2. Used when a starting water has a chloramine residual.
• tot_po4: Phosphate in mg/L as PO4 3-. Used when a starting water has a phosphate residual.
• tot_nh3: Total ammonia in mg/L as N
• tds: Total Dissolved Solids in mg/L (optional if ions are known)
• cond: Electrical conductivity in uS/cm (optional if ions are known)
• toc: Total organic carbon (TOC) in mg/L
• doc: Dissolved organic carbon (DOC) in mg/L
• uv254: UV absorbance at 254 nm (cm-1)
• br: Bromide in ug/L Br-
• f: Fluoride in mg/L F-
• fe: Iron in mg/L Fe3+
• al: Aluminum in mg/L Al3+
• mn: Manganese in ug/L Mn2+

Returns

A water class object where slots are filled or calculated based on input parameters.

Details

Carbonate balance is calculated and units are converted to mol/L. Ionic strength is determined from ions, TDS, or conductivity. Missing values are handled by defaulting to 0 or NA. Calcium hardness defaults to 65

manually specify all ions in the define_water arguments. The following equations are used to determine ionic strength: Ionic strength (if TDS provided): Crittenden et al. (2012) equation 5-38 Ionic strength (if electrical conductivity provided): Snoeyink & Jenkins (1980) Ionic strength (from ion concentrations): Lewis and Randall (1921), Crittenden et al. (2012) equation 5-37 Temperature correction of dielectric constant (relative permittivity): Harned and Owen (1958), Crittenden et al. (2012) equation 5-45.

Examples

water_missingions <- define_water(ph = 7, temp = 15, alk = 100, tds = 10)
water_defined <- define_water(7, 20, 50, 100, 80, 10, 10, 10, 10, tot_po4 = 1)