soilDB (version 2.3)

us_ss_timeline: Timeline of US Published Soil Surveys

Description

This dataset contains the years of each US Soil Survey was published.

Usage

data("us_ss_timeline")

Format

A data frame with 5209 observations on the following 5 variables.

ssa

Soil Survey name, a character vector

year

year of publication, a numeric vector

pdf

does a pdf exists, a logical vector

state

State abbrevation, a character vector

Details

This data was web scraped from the NRCS Soils Website. The scraping procedure and a example plot are included in the examples section below.

Examples

# NOT RUN {
library(XML)
library(RCurl)
library(ggplot2)

data(state)
st <- paste0(c(state.abb, "PR", "DC", "VI", "PB"))
us_ss_timeline <- {
  lapply(st, function(x) {
    cat("getting", x, "\n")
    url <- getURL(paste0(
    "https://www.nrcs.usda.gov/wps/portal/nrcs/surveylist/soils/survey/state/?stateId=", x)
    )
    df  <- readHTMLTable(url, which = 22, stringsAsFactors = FALSE)
    df$state <- x
    return(df)
    }) ->.;
  do.call("rbind", .) ->.;
  names(.) <- c("ssa", "year", "pdf", "wss", "state")
  .[.$year != "current", ] ->.;
  }
us_ss_timeline <- within(us_ss_timeline, {
  ssa  = sapply(ssa, function(x) strsplit(x, "\r")[[1]][1])
  year = as.numeric(year)
  pdf  = ifelse(pdf == "Yes", TRUE, FALSE)
  wss  = NULL
  })

test <- as.data.frame(table(us_ss_timeline$year), stringsAsFactors = FALSE)

g1 <- ggplot(test, aes(x = as.numeric(Var1), y = Freq)) +
  geom_histogram(stat = "identity") + 
  xlab("Year") + 
  ylab("Count") +
  theme(aspect.ratio = 1) + 
  ggtitle("Number of Published \n US Soil Surveys by Year")
g2 <- ggplot(test, aes(x = as.numeric(Var1), y = cumsum(Freq))) +
  geom_histogram(stat = "identity") + 
  xlab("Year") + 
  ylab("Count") +
  theme(aspect.ratio = 1) +
  ggtitle("Cumulative Number of Published \n US Soil Surveys by Year")
gridExtra::grid.arrange(g1, g2, ncol = 2)

# }