Return requested NHDPlusV2 Attributes.
get_vaa(
atts = NULL,
path = get_vaa_path(),
download = TRUE,
updated_network = FALSE
)character The variable names you would like, always includes comid
character path where the file should be saved. Default is a persistent system data as retrieved by nhdplusTools_data_dir. Also see: get_vaa_path
logical if TRUE, the default, will download VAA table if not found at path.
logical default FALSE. If TRUE, updated network attributes from E2NHD and National Water Model retrieved from doi:10.5066/P976XCVT .
data.frame containing requested VAA data
The VAA data is a aggregate table of information from the NHDPlusV2
elevslope.dbf(s), PlusFlowlineVAA.dbf(s); and NHDFlowlines. All data
originates from the EPA NHDPlus Homepage
here.
To see the location of cached data on your machine use
get_vaa_path.
To view aggregate data and documentation, see
here
if (FALSE) {
# This will download the vaa file to the path from get_vaa_path()
get_vaa("slope")
get_vaa(c("slope", "lengthkm"))
get_vaa(updated_network = TRUE)
get_vaa("reachcode", updated_network = TRUE)
#cleanup if desired
unlink(dirname(get_vaa_path()), recursive = TRUE)
}