Reads peak flow from NWISweb. Data is retrieved from https://waterdata.usgs.gov/nwis. In some cases, the specific date of the peak data is not know. This function will default to converting complete dates to a "Date" object, and converting incomplete dates to "NA". If those incomplete dates are needed, set the `asDateTime` argument to FALSE. No dates will be converted to R Date objects.
Usage
readNWISpeak(
siteNumbers,
startDate = "",
endDate = "",
asDateTime = TRUE,
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.
- asDateTime
logical default to
TRUE
. WhenTRUE
, the peak_dt column is converted to a Date object, and incomplete dates are removed. WhenFALSE
, no columns are removed, but no dates are converted.- convertType
logical, defaults to
TRUE
. IfTRUE
, 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 |
peak_dt | Date | Date of peak streamflow |
peak_tm | character | Time of peak streamflow as character |
peak_va | numeric | Annual peak streamflow value in cfs |
peak_cd | character | Peak Discharge-Qualification codes (see comment
for more information) |
gage_ht | numeric | Gage height for the associated peak streamflow in feet |
gage_ht_cd | character | Gage height qualification codes |
year_last_pk | numeric | Peak streamflow reported is the highest since this year |
ag_dt | Date | Date of maximum gage-height for water year (if not concurrent with peak) |
ag_tm | character | Time of maximum gage-height for water year (if not concurrent with peak) |
ag_gage_ht | numeric | maximum Gage height for water year in feet (if not concurrent with peak) |
ag_gage_ht_cd | character | maximum Gage height code |
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 |
Examples
site_ids <- c("01594440", "040851325")
# \donttest{
data <- readNWISpeak(site_ids)
#> GET: https://nwis.waterdata.usgs.gov/usa/nwis/peak/?site_no=01594440,040851325&range_selection=date_range&format=rdb
data2 <- readNWISpeak(site_ids, asDateTime = FALSE)
#> GET: https://nwis.waterdata.usgs.gov/usa/nwis/peak/?site_no=01594440,040851325&range_selection=date_range&format=rdb
stations <- c("06011000")
peakdata <- readNWISpeak(stations, convertType = FALSE)
#> GET: https://nwis.waterdata.usgs.gov/usa/nwis/peak/?site_no=06011000&range_selection=date_range&format=rdb
# }