Return requested NHDPlusv2 Attributes.

get_vaa(
  atts = NULL,
  path = get_vaa_path(),
  download = TRUE,
  updated_network = FALSE
)

Arguments

atts

character The variable names you would like, always includes comid

path

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

download

logical if TRUE, the default, will download VAA table if not found at path.

updated_network

logical default FALSE. If TRUE, updated network attributes from E2NHD and National Water Model retrieved from here.

Value

data.frame containing requested VAA data

Details

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

Examples

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)
}