agridat (version 1.25)

usgs.herbicides: Concentrations of herbicides in streams in the United States

Description

Concentrations of selected herbicides and degradation products determined by laboratory method analysis code GCS for water samples collected from 51 streams in nine Midwestern States, 2002.

Usage

data("usgs.herbicides")

Format

A data frame with 184 observations on the following 19 variables.

mapnum

map number

usgsid

USGS ID

long

longitude

lat

latitude

site

site name

city

city

sampletype

sample type code

date

date sample was collected

hour

hour sample was collected

acetochlor

concentration as character

alachlor

concentration as character

ametryn

concentration as character

atrazine

concentration as character

CIAT

concentration as character

CEAT

concentration as character

cyanazine

concentration as character

CAM

concentration as character

dimethenamid

concentration as character

flufenacet

concentration as character

Details

Concentrations of selected herbicides and degradation products determined by laboratory method analysis code GCS for water samples collected from 51 streams in nine Midwestern States, 2002.

All concentrations are micrograms/liter, "<" means "less than". The data are in character format to allow for "<".

The original report contains data for more herbicides. This data is for illustrative purposes.

Sample types: CR = concurrent replicate sample, FB = field blank, LD = laboratory duplicate, S1 = sample from pre-emergence runoff, S2 = sample from post-emergence runoff, S3 = sample from harvest-season runoff.

References

None.

Examples

if (FALSE) {
  
  library(agridat)
  data(usgs.herbicides)
  dat <- usgs.herbicides

  # create censored data for one trait
  dat$y <- as.numeric(dat$atrazine)
  dat$ycen <- is.na(dat$y)
  dat$y[is.na(dat$y)] <- .05
  
#  library(NADA)
#  # percent censored
#  with(dat, censummary(y, censored=ycen))
#  # median/mean
#  with(dat, cenmle(y, ycen, dist="lognormal"))
#  # boxplot
#  with(dat, cenboxplot(obs=y, cen=ycen, log=FALSE,
#                       main="usgs.herbicides"))
#  # with(dat, boxplot(y))
#  pp <- with(dat, ros(obs=y, censored=ycen, forwardT="log")) # default lognormal
#  plot(pp)


#  plotfun <- function(vv){
#    dat$y <- as.numeric(dat[[vv]])
#    dat$ycen <- is.na(dat$y)
#    dat$y[is.na(dat$y)] <- .01
#    # qqnorm(log(dat$y), main=vv) # ordinary qq plot shows censored values
#    pp <- with(dat, ros(obs=y, censored=ycen, forwardT="log"))
#    plot(pp, main=vv) # omits censored values
#  }
#  op <- par(mfrow=c(3,3))
#  vnames <- c("acetochlor", "alachlor", "ametryn", "atrazine","CIAT", "CEAT", "cyanazine", #"CAM",
#              "dimethenamid", "flufenacet")
#  for(vv in vnames) plotfun(vv)
#  par(op)
  
}