nhd_query function

Select NHD features clipped by a circular buffer a coordinate pair

nhd_query(
  lon = NA,
  lat = NA,
  poly = NA,
  dsn,
  approve_all_dl = FALSE,
  buffer_dist = units::as_units(4.75, "km"),
  temporary = TRUE,
  ...
)

Arguments

• lon: numeric longitude
• lat: numeric latitude
• poly: sfc polygon. optional
• dsn: character data source
• approve_all_dl: logical blanket approval to download all missing data. Defaults to TRUE if session is non-interactive.
• buffer_dist: numeric buffer with specified units
• temporary: logical set FALSE to save data to a persistent rappdirs location
• ...: other arguments passed to sf::st_read

Examples

## Not run:

library(sf)
wk <- wikilake::lake_wiki("Worden Pond")
qry <- nhd_query(wk$Lon, wk$Lat, dsn = c("NHDWaterbody", "NHDFlowLine"),
  buffer_dist = units::as_units(1, "km"))
qry$sp$NHDWaterbody <- dplyr::filter(qry$sp$NHDWaterbody, FType != 466)

plot(sf::st_geometry(qry$sp$NHDWaterbody), col = "blue")
plot(sf::st_geometry(qry$sp$NHDFlowLine), col = "cyan", add = TRUE)
plot(qry$pnt, col = "red", pch = 19, add = TRUE)
axis(1)
axis(2)

# query with a polygon
wbd <- qry$sp$NHDWaterbody[
  order(st_area(qry$sp$NHDWaterbody), decreasing = TRUE), ][1, ]
qry_lines <- nhd_query(poly = st_as_sfc(st_bbox(wbd)), dsn = "NHDFlowLine")
library(ggplot2)
ggplot() +
  geom_sf(data = qry$sp$NHDWaterbody) +
  geom_sf(data = qry_lines$sp$NHDFlowLine, color = "red")
## End(Not run)