ch_checkcatchment {CSHShydRology}

Check Catchments

Description

Generates a simple map to allow a visual assessment of the catchment boundaries relative to the elevation contours.

Usage

ch_checkcatchment(
  dem,
  catchment,
  outlet,
  outlet_label = NULL,
  main_label = "",
  bbox_type = "catchment",
  channel_vec = NULL,
  cb_colour = "red",
  pp_colour = "red",
  channel_colour = "blue",
  contour_colour = "grey",
  plot_na = TRUE,
  plot_scale = TRUE,
  na_location = "tr",
  scale_location = "bl"
)

Arguments

dem

raster DEM that catchments were generated from.

catchment

Catchment polygon (sf object).

outlet

Location of catchment outlet (sf object).

outlet_label

Character label for outlet.

main_label

Main label for catchment plot.

bbox_type

type of bounding box. If catchment, then the contours are bounded by the catchment, otherwise they are plotted to the extent of the DEM

channel_vec

Vectors of the channels will be plotted if specified.

cb_colour

Colour for catchment outline. Default is "red".

pp_colour

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

channel_colour

Colour for channel. Default is "blue".

contour_colour

Colour for contours Default is "grey".

plot_na

If TRUE (the default) a north arrow is added to the plot.

plot_scale

If TRUE (the default) a scale bar is added to the plot.

na_location

Location for the north arrow. Default is tr, i.e. top-right.

scale_location

Location for the scale bar. Default is bl, i.e. bottom-left.

Details

Also generates a table summarizing the catchments, including the coordinates of the outlet point and the catchment area.

Value

TRUE. A map of the catchments is also plotted and the catchment parameters are printed.

Author(s)

Dan Moore and Kevin Shook

See Also

ch_checkchannels

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 = ".tif")
  no_sink_raster_file <- tempfile("no_sinks", fileext = ".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 = ".tif")
  flow_acc <- ch_wbt_flow_accumulation(no_sink_raster_file, flow_acc_file)

  # 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)

# get flow directions
  flow_dir_file <- tempfile("flow_dir", fileext = ".tif")
  flow_dir <- ch_wbt_flow_direction(no_sink_raster_file, flow_dir_file)
  fn_catchment_ras <- tempfile("catchment", fileext = ".tif")
  fn_catchment_vec <- tempfile("catchment", fileext = ".shp")
  catchments <- ch_wbt_catchment(snapped_pourpoint_file, flow_dir_file, 
  fn_catchment_ras, fn_catchment_vec)

# check results
  ch_checkcatchment(test_raster, catchments, snapped_pourpoints)
} else {
  message("Examples not run as Whitebox executable not found")
}