# Check Channels Generates a map of the generated channel network layer. ```r 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". ## Returns - **check_map**: a `ggplot` object of a map with channel layer ## Details Generates a simple map of the drainage network plotted over the contours to allow a visual assessment. ## Examples ```r # 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") } ``` ## See Also `ch_checkcatchment` ## Author(s) Dan Moore

ch_checkchannels function