PEC_sw_focus: Calculate PEC surface water at FOCUS Step 1

Description Usage Arguments Note References Examples

View source: R/PEC_sw_focus.R

Description

This is a reimplementation of the FOCUS Step 1 and 2 calculator version 3.2, authored by Michael Klein, in R. Note that results for multiple applications should be compared to the corresponding results for a single application. At current, this is not done automatically in this implementation. Only Step 1 PECs are calculated. However, input files are generated that are suitable as input also for Step 2 to be used with the FOCUS calculator.

Usage

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PEC_sw_focus(parent, rate, n = 1, i = NA, comment = "", met = NULL,
  f_drift = NA, f_rd = 0.1, scenario = FOCUS_Step_12_scenarios$names,
  region = c("n", "s"), season = c(NA, "of", "mm", "js"),
  interception = c("no interception", "minimal crop cover",
  "average crop cover", "full canopy"), met_form_water = TRUE,
  txt_file = "pesticide.txt", overwrite = FALSE, append = TRUE)

Arguments

parent

A list containing substance specific parameters, e.g. conveniently generated by chent_focus_sw.

rate

The application rate in g/ha. Overriden when applications are given explicitly

n

The number of applications

i

The application interval

comment

A comment for the input file

met

A list containing metabolite specific parameters. e.g. conveniently generated by chent_focus_sw. If not NULL, the PEC is calculated for this compound, not the parent.

f_drift

The fraction of the application rate reaching the waterbody via drift. If NA, this is derived from the scenario name and the number of applications via the drift data defined by the FOCUS_Step_12_scenarios

f_rd

The fraction of the amount applied reaching the waterbody via runoff/drainage. At Step 1, it is assumed to be 10 parent or a metabolite

scenario

The name of the scenario. Must be one of the scenario names given in FOCUS_Step_12_scenarios

region

'n' for Northern Europe or 's' for Southern Europe. If NA, only Step 1 PECsw are calculated

season

'of' for October to February, 'mm' for March to May, and 'js' for June to September. If NA, only step 1 PECsw are calculated

interception

One of 'no interception' (default), 'minimal crop cover', 'average crop cover' or 'full canopy'

met_form_water

Should the metabolite formation in water be taken into account? This can be switched off to check the influence and to compare with previous versions of the Steps 12 calculator

txt_file

the name, and potentially the full path to the Steps.12 input text file to which the specification of the run(s) should be written

overwrite

Should an existing file a the location specified in txt_file be overwritten? Only takes effect if append is FALSE.

append

Should the input text file be appended?

Note

The formulas for input to the waterbody via runoff/drainage of the parent and subsequent formation of the metabolite in water is not documented in the model description coming with the calculator. As one would expect, this appears to be (as we get the same results) calculated by multiplying the application rate with the molar weight correction and the formation fraction in water/sediment systems.

Step 2 is not implemented.

References

FOCUS (2014) Generic guidance for Surface Water Scenarios (version 1.4). FOrum for the Co-ordination of pesticde fate models and their USe. http://esdac.jrc.ec.europa.eu/public_path/projects_data/focus/sw/docs/Generic

Website of the Steps 1 and 2 calculator at the Joint Research Center of the European Union: http://esdac.jrc.ec.europa.eu/projects/stepsonetwo

Examples

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# Parent only
dummy_1 <- chent_focus_sw("Dummy 1", cwsat = 6000, DT50_ws = 6, Koc = 344.8)
PEC_sw_focus(dummy_1, 3000, f_drift = 0)

# Metabolite
new_dummy <- chent_focus_sw("New Dummy", mw = 250, Koc = 100)
M1 <- chent_focus_sw("M1", mw = 100, cwsat = 100, DT50_ws = 100, Koc = 50, 
  max_ws = 0, max_soil = 0.5)
PEC_sw_focus(new_dummy, 1000, scenario = "cereals, winter", met = M1)

jranke/pfm documentation built on Feb. 11, 2019, 9:11 a.m.