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Build an aspatial long-form network crosswalk

Source: R/build_aspatial_network.R
build_aspatial_network.Rd

Replaces the spatial network layer in a hydrofabric GeoPackage with an aspatial attribute table keyed on (flowline_id, reference_id), one row per sub-flowline x reference-COMID member. The table is rebuilt from the flowlines layer and the reconciled-group memberships so it always matches the trimmed topology produced by extend_flowpaths_to_mainstem: flowlines on a flowpath's mainstem levelpathid keep the mainstem's flowpath_id; flowlines on absorbed tributaries (different levelpathid) report a synthetic fp-t<levelpathid> identity and inherit the mainstem's downstream nexus as their flowpath_toid.

Output columns:

  • flowpath_id, flowpath_toid : aggregated flowpath topology

  • mainstem_id : levelpathid of the flowpath's mainstem; group all flowlines on the same mainstem channel

  • is_mainstem : TRUE when this flowline is on the flowpath's mainstem (levelpathid == mainstem_id); FALSE for absorbed tributaries

  • flowline_id, flowline_toid : split-segment topology

  • reference_id : originating reference COMID

  • reference_percent : share of reference NHD length represented by this flowline's reconciled group

  • poi_id : aggregation POI (nullable)

  • hydrolocation_id : hl_id from hydrolocations

  • divide_id, divide_areasqkm : divide this flowpath drains (all flowlines in a flowpath, mainstem and tributary: carry the same divide_id)

  • flowline_area : drainage area at flowline outlet (from FAC extraction)

Usage

build_aspatial_network(
  gpkg,
  refactored = NULL,
  reconciled = NULL,
  hydrolocations = NULL,
  verbose = FALSE
)

Arguments

gpkg

Path to the ngen GeoPackage produced by nextgen_from_gpkg.

refactored

sf of refactored flowlines from refactor_flowlines (out$refactored). Used to compute reference_percent per reference COMID.

reconciled

sf of reconciled flowlines (out$reconciled): must contain ID and member_flowpath_id. Used to map each flowline's levelpathid back to the reference COMIDs it represents.

hydrolocations

sf of hydrolocations with poi_id and hl_id, or path to a gpkg with a hydrolocations layer. If NULL, hydrolocation_id is sourced from the events layer if present.

verbose

If TRUE, emit a rich breakdown: row class counts, tributary-flowline share, reference_percent distribution, hydrolocation match rate, divide-area / flowline-area summaries. Default FALSE.

Value

Invisibly, the path to gpkg.

Examples

if (FALSE) { # \dontrun{
build_aspatial_network(
  gpkg           = "ngen_vpu01.gpkg",
  refactored     = sf::st_read("refactored.gpkg", "refactored"),
  reconciled     = sf::st_read("reconciled.gpkg", "reconciled"),
  hydrolocations = "hydrolocations.gpkg")
} # }