ch_checkchannels {CSHShydRology}

Check Channels

Description

Generates a map of the generated channel network layer.

Usage

ch_checkchannels(
  dem,
  channels,
  outlet = NULL,
  main_label = "",
  channel_colour = "blue",
  pp_colour = "red",
  contour_colour = "grey"
)

Arguments

dem

raster DEM that catchments were generated from

channels

channel polyline (or channels list from ch_wbt_channels) (sf object)

outlet

location of catchment outlet (sf object)

main_label

Main label for channel plot.

channel_colour

Colour for channel. Default is "blue".

pp_colour

Colour for catchment pour points. Default is "red".

contour_colour

Colour for contours Default is "grey".

Details

Generates a simple map of the drainage network plotted over the contours to allow a visual assessment.

Value

check_map

a ggplot object of a map with channel layer

Author(s)

Dan Moore

See Also

ch_checkcatchment

Examples

# Only proceed if Whitebox executable is installed
library(whitebox)
if (check_whitebox_binary()){
  library(raster)
  test_raster <- ch_volcano_raster()
  dem_raster_file <- tempfile(fileext = c(".tif"))
  no_sink_raster_file <- tempfile("no_sinks", fileext = c(".tif"))

  # write test raster to file
  writeRaster(test_raster, dem_raster_file, format = "GTiff")

  # remove sinks
  removed_sinks <- ch_wbt_removesinks(dem_raster_file, no_sink_raster_file, method = "fill")

  # get flow accumulations
  flow_acc_file <- tempfile("flow_acc", fileext = c(".tif"))
  flow_acc <- ch_wbt_flow_accumulation(no_sink_raster_file, flow_acc_file)

  # get flow directions
  flow_dir_file <- tempfile("flow_dir", fileext = c(".tif"))
  flow_dir <- ch_wbt_flow_direction(no_sink_raster_file, flow_dir_file)
  channel_raster_file <- tempfile("channels", fileext = c(".tif"))
  channel_vector_file <- tempfile("channels", fileext = c(".shp"))
  channels <- ch_wbt_channels(flow_acc_file, flow_dir_file, channel_raster_file,
  channel_vector_file, 1)

  # get pour points
  pourpoint_file <- tempfile("volcano_pourpoints", fileext = ".shp")
  pourpoints <- ch_volcano_pourpoints(pourpoint_file)
  snapped_pourpoint_file <- tempfile("snapped_pourpoints", fileext = ".shp")
  snapped_pourpoints <- ch_wbt_pourpoints(pourpoints, flow_acc_file, pourpoint_file,
  snapped_pourpoint_file, snap_dist = 10)
  ch_checkchannels(test_raster, channels, snapped_pourpoints)
} else {
  message("Examples not run as Whitebox executable not found")
}