diff options
Diffstat (limited to 'R')
| -rw-r--r-- | R/PEC_sw_drainage_UK.R | 39 |
1 files changed, 30 insertions, 9 deletions
diff --git a/R/PEC_sw_drainage_UK.R b/R/PEC_sw_drainage_UK.R index d5f0bab..40835b2 100644 --- a/R/PEC_sw_drainage_UK.R +++ b/R/PEC_sw_drainage_UK.R @@ -1,7 +1,8 @@ #' Calculate initial predicted environmental concentrations in surface water due to drainage using the UK method #' #' This implements the method specified in the UK data requirements handbook and was checked against the spreadsheet -#' published on the CRC website. Degradation before the start of the drainage period is taken into account if +#' published on the CRC website. Degradation between the end (30 April) and the start (1 October) of +#' the drainage period is taken into account if #' `latest_application` is specified and the degradation parameters are given either as a `soil_DT50` or a `model`. #' #' @param rate Application rate in g/ha or with a compatible unit specified @@ -18,12 +19,12 @@ #' @return The predicted concentration in surface water in µg/L #' @references HSE's Chemicals Regulation Division (CRD) Active substance #' PECsw calculations (for UK specific authorisation requests) -#' \url{https://www.hse.gov.uk/pesticides/topics/pesticide-approvals/pesticides-registration/data-requirements-handbook/fate/active-substance-uk.htm} -#' accessed 2019-09-27 +#' \url{https://www.hse.gov.uk/pesticides/data-requirements-handbook/fate/pecsw-sed-via-drainflow.htm} +#' accessed 2026-02-13 #' -#' Drainage PECs Version 1.0 (2015) Spreadsheet published at -#' \url{https://www.hse.gov.uk/pesticides/topics/pesticide-approvals/pesticides-registration/data-requirements-handbook/fate/pec-tools-2015/PEC\%20sw-sed\%20(drainage).xlsx} -#' accessed 2019-09-27 +#' PECsw/sed spray drift and tier 1 drainflow calculator Version 2.1.1 (2025) Spreadsheet published at +#' \url{https://www.hse.gov.uk/pesticides/assets/docs/PEC%20sw-sed%20(spraydrift).xlsx)} +#' accessed 2026-02-13 #' @export #' @author Johannes Ranke #' @examples @@ -61,12 +62,13 @@ PEC_sw_drainage_UK <- function(rate, latest <- as.Date(paste(latest_application, ref_year), "%d %b %Y") if (is.na(latest)) stop("Please specify the latest application in the format '%d %b', e.g. '01 July'") tmp <- Sys.setlocale("LC_TIME", lct) - degradation_time <- as.numeric(difftime(as.Date(paste0(ref_year,"-10-01")), units = "days", latest)) + + drainage_date <- drainage_date_UK(latest) + degradation_time <- as.numeric(difftime(drainage_date, latest, units = "days")) + if (degradation_time > 0) { if (!missing(soil_DT50)) { k = log(2)/soil_DT50_d - as.Date(paste(latest_application, "1999"), "%d %B %Y") - amount_available <- amount_available * exp(-k * degradation_time) if (!missing(model)) stop("You already supplied a soil_DT50 value, implying SFO kinetics") } @@ -82,3 +84,22 @@ PEC_sw_drainage_UK <- function(rate, PEC = set_units(1e6 * (percentage_lost/100) * amount_available / volume, "\u00B5g/L") return(PEC) } + +#' @rdname PEC_sw_drainage_UK +#' @param application_date Application date +#' @export +#' @examples +#' drainage_date_UK("2023-07-10") +#' drainage_date_UK("2020-12-01") +#' drainage_date_UK(as.Date("2022-01-15")) +drainage_date_UK <- function(application_date) { + year <- substr(application_date, 1, 4) + drainage_end <- as.Date(paste0(year, "-04-30")) + drainage_start <- as.Date(paste0(year, "-10-01")) + if (application_date <= drainage_end | application_date >= drainage_start) { + drainage_date <- application_date + } else { + drainage_date <- drainage_start + } + return(drainage_date) +} |