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Get data from USGS stations

Source: R/get_mssnd_data.R
get_mssnd_data.Rd

This function is largely a wrapper function for dataRetrieval::readNWISuv, but focused on salinity at the 8 USGS stations in the Mississippi portion of the Mississippi Sound.

Usage

get_mssnd_data(
  stations = c("301001089442600", "300722089150100", "301429089145600",
    "301912088583300", "301527088521500", "302318088512600", "301849088350000",
    "301141089320300"),
  params = "00480",
  startDate = Sys.Date() %m-% months(1),
  endDate = Sys.Date(),
  tz = "America/Regina"
)

Arguments

stations

Character vector of USGS station IDs. Defaults to all 8 USGS stations located in the Mississippi portion of the Mississippi Sound.

params

Character vector of USGS parameter codes. Defaults to 00480, which corresponds to salinity.

startDate

Date object or character string in YYYY-MM-DD format. Defaults to one month ago based on the system date.

endDate

Date object or character string in YYYY-MM-DD format. Defaults to the current system date.

tz

Character string indicating the desired time zone. The underlying USGS function retrieves data in UTC, and this wrapper defaults to America/Regina - local standard time (does not adjust for daylight saving time).

Value

A named list with 2 or 3 components:

data

A data frame of raw unit-value (instantaneous) data from the USGS.

siteInfo

Metadata for the stations, extracted from the attributes of the returned data frame.

daily (Optional)

A data frame summarizing daily minimum, mean, and maximum salinity values for each site and date. This is only included if salinity data (Sal) is detected in the returned dataset.

Details

This function downloads high-frequency data via the USGS NWIS portal. It is specific to Mississippi Sound salinity data and does some processing as well. The function downloads high-frequency water quality data (typically salinity) from the USGS National Water Information System for selected monitoring stations in the Mississippi portion of the Mississippi Sound. The function returns raw data, site metadata, and (if salinity data is present) daily summaries of minimum, mean, and maximum salinity values.

The function relies on several external packages:

  • dataRetrieval for retrieving and renaming USGS data via readNWISuv() and renameNWISColumns()

  • stringr for pattern matching and replacement in variable names via str_replace() and str_detect()

  • dplyr for data manipulation, grouping, and summarizing

  • lubridate for date arithmetic

The default behavior focuses on salinity (parameter code 00480), but any other available parameters can be passed.

Examples

if (FALSE) { # \dontrun{
# Get salinity data for the past month at default stations
result <- get_mssnd_data()

# Retrieve water temp data from two stations

# View daily summary if salinity was included
head(result$daily)
} # }