R/readNWISdv.R

In dataRetrieval: Retrieval Functions for USGS and EPA Hydrology and Water Quality Data

#' Daily Value USGS NWIS Data Retrieval
#'
#' Imports data from NWIS daily web service. This function gets the data from here: 
#' \url{https://waterservices.usgs.gov/docs/dv-service/daily-values-service-details/}
#' Inputs to this function are just USGS site ids, USGS parameter codes,
#' USGS statistic codes, and start and end date. For a more complex query, use \code{\link{readNWISdata}},
#' with an argument service = "dv".
#' Data coming the daily web services are aggregates of the instantaneous
#' (sensor) web services. Not all statistical codes are available for all data.
#' Use the function \code{\link{whatNWISdata}} to discover what data
#' is available for a USGS site. The column data_type_cd with the values "dv"
#' returned from \code{\link{whatNWISdata}}) are available from this service.
#' 
#' More information on the web service can be found here:
#' \url{https://waterservices.usgs.gov/test-tools}, choosing the
#' "Daily Value Service".
#'
#' @param siteNumbers character USGS site number.  This is usually an 8 digit number.
#' Multiple sites can be requested with a character vector.
#' @param parameterCd character of USGS parameter code(s).  This is usually an 5 digit number.
#' @param startDate character starting date for data retrieval in the form YYYY-MM-DD.
#' Default is "" which indicates
#' retrieval for the earliest possible record. Date arguments are always specified in local time.
#' @param endDate character ending date for data retrieval in the form YYYY-MM-DD. Default is "" which indicates
#' retrieval for the latest possible record. Date arguments are always specified in local time.
#' @param statCd character USGS statistic code. This is usually 5 digits.  Daily mean (00003) is the default.
#' @return A data frame with the following columns:
#' \tabular{lll}{
#' Name \tab Type \tab Description \cr
#' agency \tab character \tab The NWIS code for the agency reporting the data\cr
#' site \tab character \tab The USGS site number \cr
#' Date \tab Date \tab The date of the value \cr
#' code \tab character \tab Any codes that qualify the corresponding value\cr
#' value \tab numeric \tab The numeric value for the parameter \cr
#' }
#' Note that code and value are repeated for the parameters requested. The names are of the form
#' X_D_P_S, where X is literal,
#' D is an option description of the parameter,
#' P is the parameter code,
#' and S is the statistic code (if applicable).
#'
#' There are also several useful attributes attached to the data frame:
#' \tabular{lll}{
#' Name \tab Type \tab Description \cr
#' url \tab character \tab The url used to generate the data \cr
#' siteInfo \tab data.frame \tab A data frame containing information on the requested sites \cr
#' variableInfo \tab data.frame \tab A data frame containing information on the requested parameters \cr
#' statisticInfo \tab data.frame \tab A data frame containing information on the requested statistics on the data \cr
#' queryTime \tab POSIXct \tab The time the data was returned \cr
#' }
#'
#' @seealso \code{\link{renameNWISColumns}}, \code{\link{importWaterML1}}
#' @export
#' @keywords data import USGS web service
#' @examplesIf is_dataRetrieval_user()
#' site_id <- "04085427"
#' startDate <- "2012-01-01"
#' endDate <- "2012-06-30"
#' pCode <- "00060"
#' \donttest{
#' rawDailyQ <- readNWISdv(site_id, pCode, startDate, endDate)
#' rawDailyQAndTempMeanMax <- readNWISdv(site_id, c("00010", "00060"),
#'   startDate, endDate,
#'   statCd = c("00001", "00003")
#' )
#' rawDailyQAndTempMeanMax <- renameNWISColumns(rawDailyQAndTempMeanMax)
#' rawDailyMultiSites <- readNWISdv(c("01491000", "01645000"), c("00010", "00060"),
#'   startDate, endDate,
#'   statCd = c("00001", "00003")
#' )
#' # Site with no data:
#' x <- readNWISdv("10258500", "00060", "2014-09-08", "2014-09-14")
#' names(attributes(x))
#' attr(x, "siteInfo")
#' attr(x, "variableInfo")
#'
#' site <- "05212700"
#' notActive <- readNWISdv(site, "00060", "2014-01-01", "2014-01-07")
#' }
readNWISdv <- function(siteNumbers,
                       parameterCd,
                       startDate = "",
                       endDate = "",
                       statCd = "00003") {
  url <- constructNWISURL(
    siteNumbers = siteNumbers,
    parameterCd = parameterCd,
    startDate = startDate,
    endDate = endDate,
    service = "dv",
    statCd = statCd
  )

  data <- importWaterML1(url, asDateTime = FALSE)

  if (nrow(data) > 0) {
    data$dateTime <- as.Date(data$dateTime)
    data$tz_cd <- NULL

    names(data)[names(data) == "dateTime"] <- "Date"
  }

  return(data)
}