subset_nhdplus: Subset NHDPlus

In nhdplusTools: NHDPlus Tools

Subset NHDPlus

Description

Saves a subset of the National Seamless database or other nhdplusTools compatible data based on a specified collection of COMIDs. This function uses get_nhdplus for the "download" data source but returns data consistent with local data subsets in a subset file.

Usage

subset_nhdplus(
  comids = NULL,
  output_file = NULL,
  nhdplus_data = NULL,
  bbox = NULL,
  simplified = TRUE,
  overwrite = FALSE,
  return_data = TRUE,
  status = TRUE,
  flowline_only = NULL,
  streamorder = NULL,
  out_prj = 4269
)

Arguments

comids	integer vector of COMIDs to include.
output_file	character path to save the output to defaults to the directory of the nhdplus_data.
nhdplus_data	character path to the .gpkg or .gdb containing the national seamless database, a subset of NHDPlusHR, or "download" to use a web service to download NHDPlusV2.1 data. Not required if nhdplus_path has been set or the default has been adopted. See details for more.
bbox	object of class "bbox" as returned by sf::st_bbox in Latitude/Longitude. If no CRS is present, will be assumed to be in WGS84 Latitude Longitude.
simplified	boolean if TRUE (the default) the CatchmentSP layer will be included. Not relevant to the "download" option or NHDPlusHR data.
overwrite	boolean should the output file be overwritten
return_data	boolean if FALSE path to output file is returned silently otherwise data is returned in a list.
status	boolean should the function print status messages
flowline_only	boolean WARNING: experimental if TRUE only the flowline network and attributes will be returned
streamorder	integer only streams of order greater than or equal will be downloaded. Not implemented for local data.
out_prj	character override the default output CRS of NAD83 lat/lon (EPSG:4269)

Details

This function relies on the National Seamless Geodatabase or Geopackage. It can be downloaded here.

The "download" option of this function should be considered preliminary and subject to revision. It does not include as many layers and may not be available permanently.

Value

character path to the saved subset geopackage

Examples

source(system.file("extdata/sample_data.R", package = "nhdplusTools"))

nhdplus_path(sample_data)

sample_flines <- sf::st_zm(sf::read_sf(nhdplus_path(), "NHDFlowline_Network"))

plot(sf::st_geometry(sample_flines),
     lwd = 3)

start_point <- sf::st_sfc(sf::st_point(c(-89.362239, 43.090266)),
                          crs = 4326)

plot(start_point, cex = 1.5, lwd = 2, col = "red", add = TRUE)

start_comid <- discover_nhdplus_id(start_point)

comids <- get_UT(sample_flines, start_comid)

plot(sf::st_geometry(dplyr::filter(sample_flines, COMID %in% comids)),
     add=TRUE, col = "red", lwd = 2)

output_file <- tempfile(fileext = ".gpkg")

subset_nhdplus(comids = comids,
               output_file = output_file,
               nhdplus_data = sample_data,
               overwrite = TRUE,
               status = TRUE)

sf::st_layers(output_file)

catchment <- sf::read_sf(output_file, "CatchmentSP")

plot(sf::st_geometry(catchment), add = TRUE)

waterbody <- sf::read_sf(output_file, "NHDWaterbody")

plot(sf::st_geometry(waterbody),
     col = rgb(0, 0, 1, alpha = 0.5), add = TRUE)

# Cleanup temp
unlink(output_file)

# Download Option:
subset_nhdplus(comids = comids,
               output_file = output_file,
               nhdplus_data = "download",
               overwrite = TRUE,
               status = TRUE, flowline_only = FALSE)

sf::st_layers(output_file)

# NHDPlusHR
source(system.file("extdata/nhdplushr_data.R", package = "nhdplusTools"))

up_ids <- get_UT(hr_data$NHDFlowline, 15000500028335)

sub_gpkg <- file.path(work_dir, "sub.gpkg")
sub_nhdhr <- subset_nhdplus(up_ids, output_file = sub_gpkg,
                            nhdplus_data = hr_gpkg, overwrite = TRUE)

sf::st_layers(sub_gpkg)
names(sub_nhdhr)

plot(sf::st_geometry(hr_data$NHDFlowline), lwd = 0.5)
plot(sf::st_geometry(sub_nhdhr$NHDFlowline), lwd = 0.6, col = "red", add = TRUE)

unlink(output_file)
unlink(sub_gpkg)

nhdplusTools documentation built on June 22, 2024, 10:36 a.m.