split_flowlines: Split Flowlines

In dblodgett-usgs/hyRefactor: Hydrologic Network Refactoring Tools Based on HY_Features

Split Flowlines

Description

A wrapper for split_lines that works on nhdplus attributes

Usage

split_flowlines(flines, max_length = NULL, events = NULL, para = 0, avoid = NA)

Arguments

flines	data.frame with COMID, toCOMID, LENGTHKM and LINESTRING sf column in "meters" projection
max_length	maximum segment length to return
events	data.frame containing events as generated by nhdplusTools::get_flowline_index() if an 'identifier' attribute is included, it will be passed through in the output table.
para	numeric how many threads to use in parallel computation
avoid	vector of ids to avoid

Value

All the flowlines with some split apart. COMIDs are returned as strings with a semantic part number appended. That is .1, .2, ... .10, .11, etc. are appended and must be treated as one would treat a semantic version. .1 is the most upstream and the sequence increases in the downstream direction.

See Also

The refactor_nhdplus function implements a complete workflow using 'split_flowlines()'.

Examples

source(system.file("extdata", "new_hope_data.R", package = "hyRefactor"))

new_hope_flowline <- 
  dplyr::right_join(dplyr::select(new_hope_flowline, COMID, REACHCODE, FromMeas, ToMeas),
                    suppressWarnings(nhdplusTools::prepare_nhdplus(
                      new_hope_flowline, 0, 0, 0, FALSE, warn = FALSE)),
                    by = "COMID")

split <- split_flowlines(suppressWarnings(sf::st_cast(sf::st_transform(
  new_hope_flowline, 5070), "LINESTRING")),
                         max_length = 2000, events = new_hope_events)

dblodgett-usgs/hyRefactor documentation built on Aug. 25, 2023, 9:09 p.m.