diff options
Diffstat (limited to 'R')
| -rw-r--r-- | R/PEC_sw_drift.R | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/R/PEC_sw_drift.R b/R/PEC_sw_drift.R index eccb5bf..22aa012 100644 --- a/R/PEC_sw_drift.R +++ b/R/PEC_sw_drift.R @@ -8,15 +8,19 @@ #' @seealso [drift_parameters_focus], [drift_percentages_rautmann] #' @param rate Application rate in units specified below #' @param drift_percentages Percentage drift values for which to calculate PECsw. -#' 'drift_data' and 'distances' if not NULL. +#' Overrides 'drift_data' and 'distances' if not NULL. #' @param drift_data Source of drift percentage data. If 'JKI', the [drift_data_JKI] -#' included in the package is used. If 'RF', the Rautmann formula is used, if -#' implemented for the crop type and number of applications +#' 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. #' @param crop_group_JKI When using the 'JKI' drift data, one of the German names #' as used in [drift_parameters_focus]. #' @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 +#' @param water_width Width of the water body in cm +#' @param 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. #' @return The predicted concentration in surface water #' @export #' @author Johannes Ranke @@ -35,6 +39,14 @@ #' #' # 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)) +#' +#' # 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) +#' PEC_sw_drift(100, drift_data = "RF") +#' PEC_sw_drift(100, drift_data = "RF", formula = "FOCUS") +#' PEC_sw_drift(100, drift_data = "RF", formula = "FOCUS", side_angle = 45) +#' PEC_sw_drift(100, drift_data = "RF", formula = "FOCUS", side_angle = 45, water_width = 200) PEC_sw_drift <- function(rate, applications = 1, water_depth = 30, @@ -46,6 +58,9 @@ PEC_sw_drift <- function(rate, 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 = "\u00B5g/L") { @@ -54,14 +69,20 @@ PEC_sw_drift <- function(rate, drift_data <- match.arg(drift_data) crop_group_JKI <- match.arg(crop_group_JKI) crop_group_focus <- match.arg(crop_group_focus) - water_volume <- 100 * 100 * (water_depth/100) * 1000 # in L (for 1 ha) + formula <- match.arg(formula) + if (side_angle < 0 | side_angle > 90) stop("The side anglemust be between 0 and 90 degrees") + mean_water_width <- if (side_angle == 90) water_width + else water_width - (water_depth / tanpi(side_angle/180)) + water_volume <- 100 * mean_water_width * (water_depth/100) * 1000 # in L (for 1 ha) PEC_sw_overspray <- rate * 1e6 / water_volume # in µg/L dist_index <- as.character(distances) if (is.null(drift_percentages)) { drift_percentages <- switch(drift_data, JKI = pfm::drift_data_JKI[[applications]][dist_index, crop_group_JKI], - RF = drift_percentages_rautmann(distances, applications, crop_group_focus) + RF = drift_percentages_rautmann(distances, applications, + formula = formula, + crop_group_focus, widths = water_width/100) ) names(drift_percentages) <- paste(dist_index, "m") } else { |