Groundwater level measurements retrieval from USGS (NWIS)

Imports groundwater level data from NWIS web service. This function gets the data from here: https://waterservices.usgs.gov/docs/groundwater-levels/groundwater-levels-details/ Inputs to this function are just USGS site ids, USGS parameter codes, and start and end date. For a more complex query, use readNWISdata, including an argument service="gwlevels". Not all parameter codes are available for all data. Use the function whatNWISdata to discover what data is available for a USGS site. The column data_type_cd with the values "gw" returned from whatNWISdata) are available from this service.

Usage

readNWISgwl(
  siteNumbers,
  startDate = "",
  endDate = "",
  parameterCd = NA,
  convertType = TRUE,
  tz = "UTC"
)

Arguments

siteNumbers

character USGS site number (or multiple sites). This is usually an 8 digit number

startDate

character starting date for data retrieval in the form YYYY-MM-DD. Default is "" which indicates retrieval for the earliest possible record.

endDate

character ending date for data retrieval in the form YYYY-MM-DD. Default is "" which indicates retrieval for the latest possible record.

parameterCd

character USGS parameter code. This is usually an 5 digit number. Default is "".

convertType

logical, defaults to TRUE. If TRUE, the function will convert the data to dates, datetimes, numerics based on a standard algorithm. If false, everything is returned as a character

tz

character to set timezone attribute of dateTime. Default is "UTC", and converts the date times to UTC, properly accounting for daylight savings times based on the data's provided tz_cd column. Possible values to provide are "America/New_York", "America/Chicago", "America/Denver", "America/Los_Angeles", "America/Anchorage", as well as the following which do not use daylight savings time: "America/Honolulu", "America/Jamaica", "America/Managua", "America/Phoenix", and "America/Metlakatla". See also OlsonNames() for more information on time zones.

Value

A data frame with the following columns:

Name	Type	Description
agency_cd	character	The NWIS code for the agency reporting the data
site_no	character	The USGS site number
site_tp_cd	character	Site type code
lev_dt	Date	Date level measured
lev_tm	character	Time level measured
lev_tz_cd	character	Time datum
lev_va	numeric	Water level value in feet below land surface
sl_lev_va	numeric	Water level value in feet above specific vertical datum
lev_status_cd	character	The status of the site at the time the water level was measured
lev_agency_cd	character	The agency code of the person measuring the water level

There are also several useful attributes attached to the data frame:

Name	Type	Description
url	character	The url used to generate the data
queryTime	POSIXct	The time the data was returned
comment	character	Header comments from the RDB file
siteInfo	data.frame	A data frame containing information on the requested sites

Details

More information on the web service can be found here: https://waterservices.usgs.gov/test-tools, choosing the "Groundwater Levels Value Service".

Mixed date/times come back from the service depending on the year that the data was collected. See https://waterdata.usgs.gov/usa/nwis/gw for details about groundwater. By default the returned dates are converted to date objects, unless convertType is specified as FALSE. Sites with non-standard date formats (i.e. lacking a day) can be affected (see examples). See https://waterservices.usgs.gov/docs/groundwater-levels/ for more information.

See also

constructNWISURL, importRDB1

Examples

site_id <- "434400121275801"
# \donttest{
data <- readNWISgwl(site_id)
#> GET: https://nwis.waterdata.usgs.gov/nwis/gwlevels?site_no=434400121275801&format=rdb&group_key=NONE&date_format=YYYY-MM-DD&rdb_compression=value
sites <- c("434400121275801", "375907091432201")
data2 <- readNWISgwl(sites, "", "")
#> GET: https://nwis.waterdata.usgs.gov/nwis/gwlevels?site_no=434400121275801,375907091432201&format=rdb&group_key=NONE&date_format=YYYY-MM-DD&rdb_compression=value
data3 <- readNWISgwl("420125073193001", "", "")
#> GET: https://nwis.waterdata.usgs.gov/nwis/gwlevels?site_no=420125073193001&format=rdb&group_key=NONE&date_format=YYYY-MM-DD&rdb_compression=value
# handling of data where date has no day
data4 <- readNWISgwl("425957088141001", startDate = "1980-01-01")
#> GET: https://nwis.waterdata.usgs.gov/nwis/gwlevels?site_no=425957088141001&format=rdb&begin_date=1980-01-01&group_key=NONE&date_format=YYYY-MM-DD&rdb_compression=value
#> Not all dates were converted to Date object. Returning raw text for date columns.

data5 <- readNWISgwl("263819081585801", parameterCd = "72019")
#> GET: https://nwis.waterdata.usgs.gov/nwis/gwlevels?site_no=263819081585801&format=rdb&group_key=NONE&date_format=YYYY-MM-DD&rdb_compression=value
# }