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This is a basic, vectorised form of a simple calculation of a contaminant concentration in surface water based on complete, instantaneous mixing with input via spray drift.

Usage

PEC_sw_drift(
  rate,
  applications = 1,
  water_depth = 30,
  drift_percentages = NULL,
  drift_data = c("JKI", "RF"),
  crop_group_JKI = c("Ackerbau", "Obstbau frueh", "Obstbau spaet", "Weinbau frueh",
    "Weinbau spaet", "Hopfenbau", "Flaechenkulturen > 900 l/ha", "Gleisanlagen"),
  crop_group_focus = c("arable", "hops", "vines, late", "vines, early", "fruit, late",
    "fruit, early", "aerial"),
  distances = c(1, 5, 10, 20),
  formula = c("Rautmann", "FOCUS"),
  water_width = 100,
  side_angle = 90,
  rate_units = "g/ha",
  PEC_units = "µg/L"
)

Arguments

rate

Application rate in units specified below

applications

Number of applications for selection of drift percentile

water_depth

Depth of the water body in cm

drift_percentages

Percentage drift values for which to calculate PECsw. Overrides 'drift_data' and 'distances' if not NULL.

drift_data

Source of drift percentage data. If 'JKI', the drift_data_JKI included in the package is used. If 'RF', the Rautmann drift data are calculated either in the original form or integrated over the width of the water body, depending on the 'formula' argument.

crop_group_JKI

When using the 'JKI' drift data, one of the German names as used in drift_parameters_focus.

crop_group_focus

One of the crop groups as used in drift_parameters_focus

distances

The distances in m for which to get PEC values

formula

By default, the original Rautmann formula is used. If you specify "FOCUS", mean drift input over the width of the water body is calculated as described in Chapter 5.4.5 of the FOCUS surface water guidance

water_width

Width of the water body in cm

side_angle

The angle of the side of the water relative to the bottom which is assumed to be horizontal, in degrees. The SYNOPS model assumes 45 degrees here.

rate_units

Defaults to g/ha

PEC_units

Requested units for the calculated PEC. Only µg/L currently supported

Value

The predicted concentration in surface water

Author

Johannes Ranke

Examples

PEC_sw_drift(100)
#>        1 m        5 m       10 m       20 m 
#> 0.92333333 0.19000000 0.09666667 0.05000000 
# Alternatively, we can use the formula for a single application to
# "Ackerbau" from the paper
PEC_sw_drift(100, drift_data = "RF")
#>        1 m        5 m       10 m       20 m 
#> 0.91976667 0.19064473 0.09680051 0.04915079 

# This makes it possible to also use different distances
PEC_sw_drift(100, distances = c(1, 3, 5, 6, 10, 20, 50, 100), drift_data = "RF")
#>        1 m        3 m        5 m        6 m       10 m       20 m       50 m 
#> 0.91976667 0.31415827 0.19064473 0.15951494 0.09680051 0.04915079 0.02006434 
#>      100 m 
#> 0.01018774 

# or consider aerial application
PEC_sw_drift(100, distances = c(1, 3, 5, 6, 10, 20, 50, 100), drift_data = "RF", 
  crop_group_focus = "aerial")
#>        1 m        3 m        5 m        6 m       10 m       20 m       50 m 
#> 16.8233333 11.0585820  9.0986174  8.4866460  6.9825178  4.7004640  1.8820816 
#>      100 m 
#>  0.9417586 

# Using custom drift percentages is also supported
PEC_sw_drift(100, drift_percentages = c(2.77, 0.95, 0.57, 0.48, 0.29, 0.15, 0.06, 0.03))
#>     2.77 %     0.95 %     0.57 %     0.48 %     0.29 %     0.15 %     0.06 % 
#> 0.92333333 0.31666667 0.19000000 0.16000000 0.09666667 0.05000000 0.02000000 
#>     0.03 % 
#> 0.01000000 

# The influence of assuming a 45° angle of the sides of the waterbody and the width of the 
# waterbody can be illustrated
PEC_sw_drift(100)
#>        1 m        5 m       10 m       20 m 
#> 0.92333333 0.19000000 0.09666667 0.05000000 
PEC_sw_drift(100, drift_data = "RF")
#>        1 m        5 m       10 m       20 m 
#> 0.91976667 0.19064473 0.09680051 0.04915079 
PEC_sw_drift(100, drift_data = "RF", formula = "FOCUS")
#>        1 m        5 m       10 m       20 m 
#> 0.64246407 0.17414541 0.09235842 0.04798749 
PEC_sw_drift(100, drift_data = "RF", formula = "FOCUS", side_angle = 45)
#>        1 m        5 m       10 m       20 m 
#> 0.91780582 0.24877916 0.13194060 0.06855356 
PEC_sw_drift(100, drift_data = "RF", formula = "FOCUS", side_angle = 45, water_width = 200)
#>        1 m        5 m       10 m       20 m 
#> 0.30085000 0.09468652 0.05201349 0.02758547