1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
#' 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.
#'
#' @inheritParams drift_percentages_rautmann_formula
#' @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.
#' @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
#' @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
#' @return The predicted concentration in surface water
#' @export
#' @author Johannes Ranke
#' @examples
#' PEC_sw_drift(100)
#' # Alternatively, we can use the formula for a single application to "Ackerbau" from the paper
#' PEC_sw_drift(100, drift_data = "RF")
#'
#' # This makes it possible to also use different distances
#' PEC_sw_drift(100, distances = c(1, 3, 5, 6, 10, 20, 50, 100), drift_data = "RF")
#'
#' # or consider aerial application
#' PEC_sw_drift(100, distances = c(1, 3, 5, 6, 10, 20, 50, 100), drift_data = "RF",
#' crop_group_focus = "aerial")
#'
#' # 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))
PEC_sw_drift <- function(rate,
applications = 1,
water_depth = 30,
drift_percentages = NULL,
drift_data = c("JKI", "RF"),
crop_group_JKI = c("Ackerbau",
"Obstbau frueh", "Obstbau spaet", "Weinbau frueh", "Weinbau spaet",
"Hopfenbau", "Flaechenkulturen > 900 l/ha", "Gleisanlagen"),
crop_group_focus = c("arable", "hops", "vines, late", "vines, early",
"fruit, late", "fruit, early", "aerial"),
distances = c(1, 5, 10, 20),
rate_units = "g/ha",
PEC_units = "\u00B5g/L")
{
rate_units <- match.arg(rate_units)
PEC_units <- match.arg(PEC_units)
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)
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_formula(distances, applications, crop_group_focus)
)
names(drift_percentages) <- paste(dist_index, "m")
} else {
names(drift_percentages) <- paste(drift_percentages, "%")
}
PEC_sw_drift <- PEC_sw_overspray * drift_percentages / 100
return(PEC_sw_drift)
}
#' Calculate the drift percentages according to the Rautmann formula
#'
#' @param distances The distances in m for which to get PEC values
#' @param applications Number of applications for selection of drift percentile
#' @param crop_group_focus One of the crop groups as used in [drift_parameters_focus]
#' @export
#' @examples
# # One application on field crops, for 1 m, 3 m and 5 m distance
#' drift_data_JKI[[1]][as.character(c(1, 3, 5)), "Ackerbau"]
#' drift_percentages_rautmann_formula(c(1, 3, 5))
#'
#' # One application to early or late fruit crops
#' drift_data_JKI[[1]][as.character(c(3, 5, 20, 50)), "Obstbau frueh"]
#' drift_percentages_rautmann_formula(c(3, 5, 20, 50), crop_group = "fruit, early")
#' drift_data_JKI[[1]][as.character(c(3, 5, 20, 50)), "Obstbau spaet"]
#' drift_percentages_rautmann_formula(c(3, 5, 20, 50), crop_group = "fruit, late")
drift_percentages_rautmann_formula <- function(distances, applications = 1,
crop_group_focus = c("arable", "hops", "vines, late", "vines, early", "fruit, late",
"fruit, early", "aerial"))
{
cg <- match.arg(crop_group_focus)
if (!applications %in% 1:8) stop("Only 1 to 8 applications are supported")
parms <- pfm::drift_parameters_focus[pfm::drift_parameters_focus$crop_group == cg &
pfm::drift_parameters_focus$n_apps == applications, c("A", "B", "C", "D", "hinge")]
drift_percentages = with(as.list(parms), {
A <- ifelse(distances < hinge, A, C)
B <- ifelse(distances < hinge, B, D)
A * distances^B
}
)
return(drift_percentages)
}
|
