check_compl_confluences: Check if there are more than two inflows to an outflow.

In openSTARS: An Open Source Implementation of the 'ArcGIS' Toolbox 'STARS'

Description

It is checked, if more than two line segments flow into a node, i.e. if there are more than two inflows to an outflow.

Usage

check_compl_confluences()

Details

It is checked, if there are columns named 'prev_str03', 'prev_str04' and 'prev_str05' in the attribute table of streams_v derived with derive_streams (i.e. based on the GRASS function r.stream.order).

Value

TRUE if there are complex confluences.

Note

setup_grass_environment, import_data and derive_streams must be run before.

Author(s)

Mira Kattwinkel [e-mail]

Examples

# Initiate and setup GRASS
dem_path <- system.file("extdata", "nc", "elev_ned_30m.tif", package = "openSTARS")
if(.Platform$OS.type == "windows"){
  grass_program_path = "c:/Program Files/GRASS GIS 7.6"
  } else {
  grass_program_path = "/usr/lib/grass78/"
  }

setup_grass_environment(dem = dem_path, 
                        gisBase = grass_program_path,      
                        remove_GISRC = TRUE,
                        override = TRUE
                        )
gmeta()

# Load files into GRASS
dem_path <- system.file("extdata", "nc", "elev_ned_30m.tif", package = "openSTARS")
sites_path <- system.file("extdata", "nc", "sites_nc.shp", package = "openSTARS")
import_data(dem = dem_path, sites = sites_path)

# Derive streams from DEM
derive_streams(burn = 0, accum_threshold = 700, condition = TRUE, clean = TRUE)

check_compl_confluences()

# Deriving streams with finer resolution will result in complext confluences
 derive_streams(burn = 0, accum_threshold = 150, condition = TRUE, clean = TRUE)
 check_compl_confluences()

openSTARS documentation built on Feb. 4, 2022, 5:08 p.m.