diff options
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/DESCRIPTION | 4 | ||||
| -rw-r--r-- | pkg/R/PEC_sw_drift_NL.R | 49 |
2 files changed, 51 insertions, 2 deletions
diff --git a/pkg/DESCRIPTION b/pkg/DESCRIPTION index 99650ab..e597f10 100644 --- a/pkg/DESCRIPTION +++ b/pkg/DESCRIPTION @@ -1,8 +1,8 @@ Package: pfm Type: Package Title: Utilities for Pesticide Fate Modelling -Version: 0.3-3 -Date: 2016-03-02 +Version: 0.3-4 +Date: 2016-03-10 Authors@R: person("Johannes Ranke", email = "jranke@uni-bremen.de", role = c("aut", "cre", "cph")) Description: Utilities for simple calculations of predicted environmental diff --git a/pkg/R/PEC_sw_drift_NL.R b/pkg/R/PEC_sw_drift_NL.R new file mode 100644 index 0000000..cc92185 --- /dev/null +++ b/pkg/R/PEC_sw_drift_NL.R @@ -0,0 +1,49 @@ +# Copyright (C) 2016 Johannes Ranke +# Contact: jranke@uni-bremen.de +# This file is part of the R package pfm + +# This program is free software: you can redistribute it and/or modify it under +# the terms of the GNU General Public License as published by the Free Software +# Foundation, either version 3 of the License, or (at your option) any later +# version. + +# This program is distributed in the hope that it will be useful, but WITHOUT +# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more +# details. + +# You should have received a copy of the GNU General Public License along with +# this program. If not, see <http://www.gnu.org/licenses/> + +#' Calculate predicted environmental concentrations in surface water due to drift +#' +#' 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. +#' +#' @param rate Application rate in units specified below +#' @param applications Number of applications for selection of drift percentile +#' @param drift_percentages Percentage drift values for which to calculate PECsw +#' @param water_depth Depth of the water body in cm +#' @param rate_units Defaults to g/ha +#' @param PEC_units Requested units for the calculated PEC. Only µg/L currently supported +#' @return The predicted concentration in surface water +#' @export +#' @author Johannes Ranke +#' @examples +#' PEC_sw_drift_NL(100) +PEC_sw_drift_NL <- function(rate, + applications = 1, + water_depth = 30, + drift_percentages = c(1), + rate_units = "g/ha", + PEC_units = "\u00B5g/L") +{ + rate_units <- match.arg(rate_units) + PEC_units <- match.arg(PEC_units) + water_volume <- 100 * 100 * (water_depth/100) * 1000 # in L (for 1 ha) + PEC_sw_overspray <- rate * 1e6 / water_volume # in µg/L + PEC_sw_drift <- PEC_sw_overspray * drift_percentages / 100 + names(PEC_sw_drift) <- paste(drift_percentages, "%") + return(PEC_sw_drift) +} |