hydroloom (version 1.1.0)

add_levelpaths: Add Level Paths

Description

Assigns level paths using the stream-leveling approach of NHD and NHDPlus. If arbolate sum is provided in the weight column, this will match the behavior of NHDPlus. Any numeric value can be included in this column and the largest value will be followed when no nameid is available.

x must include id, toid, and conditionally divergence attributes. If a "topo_sort" (hydrosequence in nhdplus terms) attribute is included, it will be used instead of recreation.

If a future plan is set, it will be used for a preprocess step of the function.

Usage

add_levelpaths(
  x,
  name_attribute,
  weight_attribute,
  override_factor = NULL,
  status = FALSE
)
# S3 method for data.frame
add_levelpaths(
  x,
  name_attribute,
  weight_attribute,
  override_factor = NULL,
  status = FALSE
)
# S3 method for hy
add_levelpaths(
  x,
  name_attribute,
  weight_attribute,
  override_factor = NULL,
  status = FALSE
)

Value

data.frame with id, levelpath_outlet_id, topo_sort, and levelpath columns. See details for more info.

Arguments

x

data.frame network compatible with hydroloom_names.

name_attribute

character attribute to be used as name identifiers.

weight_attribute

character attribute to be used as weight.

override_factor

numeric multiplier to use to override name_attribute. See details.

status

boolean if status updates should be printed.

Details

The levelpath algorithm defines upstream mainstem paths through a network. At a given junction with two or more upstream flowpaths, the main path is either 1) the path with the same name, 2) the path with any name, 3) or the path with the larger weight. If the weight_attribute is override_factor times larger on a path, it will be followed regardless of the name_attribute indication.

If id and toid are non-dendritic so id:toid is many to one and id is non-unique, a divergence attribute must be included such that the dendritic network can be extracted after the network is sorted.

Examples

g <- sf::read_sf(system.file("extdata/new_hope.gpkg", package = "hydroloom"))

test_flowline <- add_toids(g)

# use NHDPlus attributes directly
add_levelpaths(test_flowline,
               name_attribute = "GNIS_ID",
               weight_attribute = "ArbolateSu")

# use hy attributes where they can be mapped
add_levelpaths(hy(test_flowline),
               name_attribute = "GNIS_ID",
               weight_attribute = "arbolate_sum")