This is a reimplementation of the calculation described in the Exposit 3.02 spreadsheet file, in the worksheet "Konzept Runoff".

PEC_sw_exposit_runoff(rate, interception = 0, Koc, DT50 = Inf,
  t_runoff = 3, exposit_reduction_version = c("3.02", "3.01a",
  "3.01a2", "2.0"), V_ditch = 30, V_event = 100, dilution = 2)

Arguments

rate

The application rate in g/ha

interception

The fraction intercepted by the crop

Koc

The sorption coefficient to soil organic carbon

DT50

The soil half-life in days

t_runoff

The time between application and the runoff event, where degradation occurs, in days

exposit_reduction_version

The version of the reduction factors to be used. "3.02" is the current version used in Germany, "3.01a" is the version with additional percentages for 3 m and 6 m buffer zones used in Switzerland. "3.01a2" is a version introduced for consistency with previous calculations performed for a 3 m buffer zone in Switzerland, with the same reduction being applied to the dissolved and the bound fraction.

V_ditch

The volume of the ditch is assumed to be 1 m * 100 m * 30 cm = 30 m3

V_event

The unreduced runoff volume, equivalent to 10 mm precipitation on 1 ha

dilution

The dilution factor

Source

Excel 3.02 spreadsheet available from https://www.bvl.bund.de/DE/04_Pflanzenschutzmittel/03_Antragsteller/04_Zulassungsverfahren/07_Naturhaushalt/psm_naturhaush_node.html#doc1400590bodyText3

Value

A list containing the following components

perc_runoff

The runoff percentages for dissolved and bound substance

runoff

A matrix containing dissolved and bound input for the different distances

PEC_sw_runoff

A matrix containing PEC values for dissolved and bound substance for the different distances. If the rate was given in g/ha, the PECsw are in microg/L.

See also

perc_runoff_exposit for runoff loss percentages and perc_runoff_reduction_exposit for runoff reduction percentages used

Examples

PEC_sw_exposit_runoff(500, Koc = 150)
#> $perc_runoff #> dissolved bound #> 0.248 0.001 #> #> $runoff #> dissolved bound total #> No buffer 1.240 0.00500 1.24500 #> 5 m 0.744 0.00300 0.74700 #> 10 m 0.496 0.00075 0.49675 #> 20 m 0.248 0.00025 0.24825 #> #> $PEC_sw_runoff #> dissolved bound total #> No buffer 4.769231 0.019230769 4.788462 #> 5 m 4.133333 0.016666667 4.150000 #> 10 m 3.542857 0.005357143 3.548214 #> 20 m 2.480000 0.002500000 2.482500 #>
PEC_sw_exposit_runoff(600, Koc = 10000, DT50 = 195, exposit = "3.01a")
#> $perc_runoff #> dissolved bound #> 0.037 0.159 #> #> $runoff #> dissolved bound total #> No buffer 0.21964521 0.94388078 1.16352600 #> 3 m 0.16473391 0.66071655 0.82545046 #> 5 m 0.13178713 0.56632847 0.69811560 #> 6 m 0.12080487 0.42474635 0.54555122 #> 10 m 0.08785809 0.14158212 0.22944020 #> 20 m 0.04392904 0.04719404 0.09112308 #> #> $PEC_sw_runoff #> dissolved bound total #> No buffer 0.8447893 3.6303107 4.4751000 #> 3 m 0.7844472 3.1462693 3.9307165 #> 5 m 0.7321507 3.1462693 3.8784200 #> 6 m 0.7106169 2.4985080 3.2091248 #> 10 m 0.6275578 1.0113008 1.6388586 #> 20 m 0.4392904 0.4719404 0.9112308 #>