dataRetrieval (version 2.5.12)

readNWISgwl: Groundwater level measurements retrieval from USGS (NWIS)

Description

Reads groundwater level measurements from NWISweb. Mixed date/times come back from the service depending on the year that the data was collected. See http://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 http://waterservices.usgs.gov/rest/GW-Levels-Service.html for more information.

Usage

readNWISgwl(siteNumbers, startDate = "", endDate = "", convertType = TRUE)

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.

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

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	Name

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	Name

See Also

constructNWISURL, importRDB1

Examples

siteNumber <- "434400121275801"
## Not run: 
# data <- readNWISgwl(siteNumber, '','')
# sites <- c("434400121275801", "375907091432201")
# data2 <- readNWISgwl(sites, '','')
# data3 <- readNWISgwl("420125073193001", '','')
# #handling of data where date has no day
# data4 <- readNWISgwl("425957088141001", startDate = "1980-01-01") 
# ## End(Not run)