extract_network: Return nhd plus stream network upstream of a waterbody

In nhdR: Tools for Working with the National Hydrography Dataset

Return nhd plus stream network upstream of a waterbody

Description

Return nhd plus stream network upstream of a waterbody

Usage

extract_network(
  lon = NA,
  lat = NA,
  lines = NA,
  lines_network = TRUE,
  buffer_dist = 0.01,
  maxsteps = 3,
  approve_all_dl = FALSE,
  temporary = TRUE,
  ...
)

Arguments

lon	numeric decimal degree longitude
lat	numeric decimal degree latitude
lines	sf spatial lines object to limit extent of the network search
lines_network	boolean treat lines as the complete network object. If FALSE, simply start network extraction at the terminal reach of the lines object.
buffer_dist	numeric buffer around lat-lon point in dec. deg.
maxsteps	maximum number of stream climbing iterations
approve_all_dl	logical blanket approval to download all missing data. Defaults to TRUE if session is non-interactive.
temporary	logical set FALSE to save data to a persistent rappdirs location
...	parameters passed on to sf::st_read

Details

The lon and lat arguments are used for querying the corresponding lake polygon layer which is then used to climb its intersecting stream network.

Value

An sf data frame with LINESTRING geometries

Examples

## Not run: 
library(mapview)
library(sf)

# headwater lakes have no upstream network
coords <- data.frame(lat = 46.32711, lon = -89.58893)
res <- extract_network(coords$lon, coords$lat, maxsteps = 9)

# fails if no lake nhdp lake found within the buffer at the query point
coords <- data.frame(lat = 43.62453, lon = -85.47164)
res <- extract_network(coords$lon, coords$lat, maxsteps = 9)

coords <- data.frame(lat = 20.79722, lon = -156.47833)
# use a non-geographic (projected) buffer size
res <- extract_network(coords$lon, coords$lat, maxsteps = 9,
  buffer_dist = units::as_units(5, "km"))

# use a projected buffer size
res <- extract_network(coords$lon, coords$lat, maxsteps = 9)

# no upstream network for lakes intersecting the Great Lakes
coords <- data.frame(lat = 44.6265, lon = -86.23121)
res <- extract_network(coords$lon, coords$lat, maxsteps = 3)

coords <- data.frame(lat = 42.96523, lon = -89.2527)
res <- extract_network(coords$lon, coords$lat, maxsteps = 9)

mapview(res)

## End(Not run)

nhdR documentation built on Aug. 12, 2023, 9:06 a.m.