Query NHD data from an ArcGIS REST service

Usage

utilMWRgetnhd(id, bbox, dLevel, quiet = TRUE)

Arguments

id: numeric for the layer ID to query, one of 6 (flowlines), 9 (areas large scale), or 12 (waterbodies large scale)
bbox: list for the bounding box defined with elements xmin, ymin, xmax, ymax in EPSG:4326 coordinates
dLevel: character string for the desired visibiliyt leevel, one of "high", "medium", or "low", see details
quiet: logical, if FALSE progress messages are printed to the console

Value

An sf object containing the queried NHD features.

Details

Function returns NHD spatial features from the ArcGIS REST service at https://hydro.nationalmap.gov/arcgis/rest/services/nhd/MapServer. The function allows querying specific layers (flowlines, areas, waterbodies) within a defined bounding box and SQL filtering.

The dLevel argument defines the level of detail in the retrieved data. For id = 6, the visibilityFilter attribute is used to determine the detail level. If dLevel is "low", features with visibilityFilter >= 1,000,000 are returned; if "medium", features with visibilityFilter >= 500,000; and if "high", features >= 100,000 are returned. For id = 12, the SHAPE_Area attribute is used. If dLevel is "low", features with SHAPE_Area >= 300,000 are returned; if "medium", features with SHAPE_Area >= 85,000; and if "high", features with SHAPE_Area >= 10,000 are returned. No additional filtering based on detail level is applied if id = 9.

Examples

# Define bounding box (EPSG:4326)
bbox <- data.frame(
   x = c(-71.65734, -71.39113),
   y = c(42.26945, 42.46594)
 )
bbox <- sf::st_as_sf(bbox, coords = c("x", "y"), crs = 4326)
bbox <- sf::st_bbox(bbox)

if (FALSE) { # \dontrun{
flowlines <- utilMWRgetnhd(
  id = 6,
  bbox = bbox,
  dLevel = 'low'
)

area <- utilMWRgetnhd(
  id = 9,
  bbox = bbox,
  dLevel = 'low'
)

waterbody <- utilMWRgetnhd(
  id = 12,
  bbox = bbox,
  dLevel = 'low'
)
} # }