R/get_winfapapi.R
get_amax.RdThe function queries the NRFA API for the .AM file similar to the WINFAP file for a given stations. It then processes the file in a fashion similar to read_amax.
get_amax(station)a data.frame with information on the annual maxima for the station with the following columns
NRFA station number (can be a vector of station numbers)
the correct water year for the peak flow
date of maximum flow
the maximum flow in m3/s
the stage (height) reached by the river - this information is used to derive the flow via a rating curve
logical, if TRUE the water year has been flagged as rejected by the NRFA
read_amax. Information on river flow gauging in the UK and the annual maxima can be found at the National River Flow Archive website https://nrfa.ceh.ac.uk
a40003 <- get_amax(40003) # the Medway at Teston / East Farleigh
multipleStations <- get_amax(c(40003, 42003))
names(multipleStations)
#> [1] "40003" "42003"
summary(multipleStations$`42003`)
#> Station WaterYear Date
#> Min. :42003 Min. :1975 Min. :1976-09-30 21:00:00.00
#> 1st Qu.:42003 1st Qu.:1987 1st Qu.:1987-08-21 09:33:45.00
#> Median :42003 Median :1998 Median :1999-05-25 23:45:00.00
#> Mean :42003 Mean :1998 Mean :1999-07-19 13:09:03.75
#> 3rd Qu.:42003 3rd Qu.:2010 3rd Qu.:2011-05-20 23:15:00.00
#> Max. :42003 Max. :2022 Max. :2023-01-16 12:00:00.00
#> Flow Stage Rejected
#> Min. : 4.16 Min. :-9999.000 Mode :logical
#> 1st Qu.:15.69 1st Qu.: 1.241 FALSE:28
#> Median :20.60 Median : 1.382 TRUE :20
#> Mean :23.88 Mean :-1456.924
#> 3rd Qu.:28.12 3rd Qu.: 1.613
#> Max. :80.83 Max. : 2.131