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 The fraction intercepted by the crop The sorption coefficient to soil organic carbon The soil half-life in days The time between application and the runoff event, where degradation occurs, in days 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. The volume of the ditch is assumed to be 1 m * 100 m * 30 cm = 30 m3 The unreduced runoff volume, equivalent to 10 mm precipitation on 1 ha The dilution factor

## 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.

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
#>