get_vaa: NHDPlusV2 Attribute Subset

In nhdplusTools: NHDPlus Tools

NHDPlusV2 Attribute Subset

Description

Return requested NHDPlusV2 Attributes.

Usage

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 \Sexpr[results=rd]{tools:::Rd_expr_doi("10.5066/P976XCVT")}.

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

Value

data.frame containing requested VAA data

Examples

## Not run: 
# 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)

## End(Not run)

nhdplusTools documentation built on June 10, 2025, 5:11 p.m.