Create continuous Flowline Points for ordered Reaches — reach_flowline

Applies [flowline_points()] to exact saved Reach Flowlines and carries one continuous kilometer measure upstream from the selected Stream outlet.

reach_flowline_points(
  flowlines,
  dem,
  station_distance = 1,
  measure_origin = "SELECTED_STREAM_OUTLET",
  measure_offset_km = 0
)

Arguments

flowlines: Projected `sf` lines with unique `reach_id`, `ReachName` and downstream-to-upstream `reach_order` fields. Adjacent Reaches must share an exact endpoint.
dem: A single-layer `terra::SpatRaster` in the Flowline CRS.
station_distance: Maximum spacing in metres. Defaults to 1 for the FG Studio saved-Reach workflow. This does not change the explicit spacing used by existing [flowline_points()] callers such as `ohwm2`.
measure_origin: Nonempty label describing the zero-measure origin.
measure_offset_km: Non-negative kilometer measure assigned to the downstream endpoint of the first Reach. Defaults to zero for the existing single-Stream behavior.

Value

One `sf` point object containing the historical Flowline Point fields, including `POINT_M_uncalibrated` and `calibration_diff`, plus `km_to_mouth`, stable Reach identity/order, local Reach distance, explicit units, sampling interval and measure-origin label. Shared Reach endpoints occur once for each owning Reach with the same `POINT_M`.

Details

`POINT_M` and `km_to_mouth` are the same local preparation measure in kilometres from the selected Stream outlet, matching the ArcPy replacement profile. Neither field is yet a governed longitudinal-reference-frame coordinate.