dataRetrieval (version 2.5.1)

readNWISpeak: Peak flow data from USGS (NWIS)

Description

Reads peak flow from NWISweb. Data is retrieved from http://waterdata.usgs.gov/nwis. In some cases, the specific date of the peak data is not know. This function will default to converting the complete dates, dropping rows with incomplete dates. If those incomplete dates are needed, set the `asDateTime` argument to FALSE. No rows will be removed, and 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. When TRUE, the peak_dt column is converted to a Date object, and incomplete dates are removed. When FALSE, no columns are removed, but no dates are converted.

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	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	Name

See Also

constructNWISURL, importRDB1

Examples

siteNumbers <- c('01594440','040851325')
## Not run: 
# data <- readNWISpeak(siteNumbers)
# data2 <- readNWISpeak(siteNumbers, asDateTime=FALSE)
# stations<-c("06011000")
# peakdata<-readNWISpeak(stations,convertType=FALSE)
# ## End(Not run)