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

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

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

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()

MiKatt/openSTARS documentation built on June 17, 2022, 5:08 a.m.