readNWISqw: Raw Data Import for USGS NWIS QW Data

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

Raw Data Import for USGS NWIS QW Data

Description

Imports data from NWIS web service. This function gets the data from here: https://nwis.waterdata.usgs.gov/nwis/qwdata A list of parameter codes can be found here: https://nwis.waterdata.usgs.gov/nwis/pmcodes/ A list of statistic codes can be found here: https://nwis.waterdata.usgs.gov/nwis/help/?read_file=stat&format=table

Usage

readNWISqw(
  siteNumbers,
  parameterCd,
  startDate = "",
  endDate = "",
  expanded = TRUE,
  reshape = FALSE,
  tz = "UTC"
)

Arguments

siteNumbers	character of USGS site numbers. This is usually an 8 digit number
parameterCd	character that contains the code for a parameter group, or a character vector of 5-digit parameter codes. See Details.
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.
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.
expanded	logical defaults to TRUE. If TRUE, retrieves additional information. Expanded data includes remark_cd (remark code), result_va (result value), val_qual_tx (result value qualifier code), meth_cd (method code), dqi_cd (data-quality indicator code), rpt_lev_va (reporting level), and rpt_lev_cd (reporting level type). If FALSE, only returns remark_cd (remark code) and result_va (result value). Expanded = FALSE will not give sufficient information for unbiased statistical analysis.
reshape	logical, reshape the expanded data. If TRUE, then return a wide data frame with all water-quality in a single row for each sample. If FALSE (default), then return a long data frame with each water-quality result in a single row. This argument is only applicable to expanded data. Data requested using expanded=FALSE is always returned in the wide format.
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.

Details

Valid parameter code groups are "All" or group codes:

Code	Description
INF	Information
PHY	Physical
INM	Inorganics, Major, Metals
INN	Inorganics, Major, Non-metals
NUT	Nutrient
MBI	Microbiological
BIO	Biological
IMN	Inorganics, Minor, Non-metals
IMM	Inorganics, Minor, Metals
TOX	Toxicity
OPE	Organics, pesticide
OPC	Organics, PCBs
OOT	Organics, other
RAD	Radiochemistry
SED	Sediment
POP	Population/community
OTH	Other
HAB	Habitat
ISO	Stable Isotopes

If more than one parameter group is requested, only sites that data for all requested groups are returned.

Value

A data frame with at least 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
sample_dt	Date	The date the sample was collected
sample_tm	character	The reported sample collection time
startDateTime	POSIXct	Combining sample_dt and sample_tm, a date/time column is created, and converted into UTC (unless the tz argument specifies a different time zone)
endDateTime	POSIXct	If any sample_end_dt and sample_end_dt exist, this column is created similar to startDateTime

Further columns will be included depending on the requested output format (expanded = TRUE or FALSE). Columns that end in "_reported" are the originally reported timezones, but the "tz_cd" column defines the timezone of any POSIXct columns.

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
variableInfo	data frame	A data frame containing information on the requested parameters

See Also

readWQPdata, whatWQPsites, readWQPqw, constructNWISURL

dataRetrieval documentation built on Sept. 11, 2024, 7:13 p.m.