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Terrain Analysis with Stream Network Visualization

plot_slope_channels.Rd

Creates a visualization of terrain analysis including slope, contours, and stream network. This function uses pre-calculated geomorphology metrics from calc_geomorph_metrics().

Usage

plot_slope_channels(
  dtm,
  metrics,
  contour_interval = 10,
  stream_threshold = 1000,
  hillshade_angle = 45,
  hillshade_direction = 270,
  contour_color = "darkorange4",
  contour_width = 1,
  label_size = 0.8,
  slope_alpha = 0.6,
  stream_color = "blue",
  stream_width = 1,
  main_title = "Slope with contours and streams"
)

Arguments

dtm

SpatRaster. dtm raster object from the terra package.

metrics

Optional. A list object returned from calc_geomorph_metrics(). If NULL, the function will calculate metrics internally. Default is NULL.

contour_interval

Numeric. Elevation interval for contour lines. Default is 10.

stream_threshold

Numeric. Threshold value for stream extraction (number of cells). Higher values result in fewer streams. Default is 1000.

hillshade_angle

Numeric. Sun elevation angle for hillshade calculation (0-90 degrees). Default is 45.

hillshade_direction

Numeric. Sun azimuth direction for hillshade (0-360 degrees). Default is 270.

contour_color

Character. Color for contour lines. Default is "darkorange4".

contour_width

Numeric. Line width for contours. Default is 1.

label_size

Numeric. Size of contour labels. Default is 0.8.

slope_alpha

Numeric. Transparency of slope overlay (0-1). Default is 0.6.

stream_color

Character. Color for stream network. Default is "blue".

stream_width

Numeric. Line width for streams. Default is 1.

main_title

Character. Plot title. Default is "Slope with contours and streams".

Value

A named list containing:

  • dtm: Original dtm as SpatRaster

  • slope: Slope in degrees as SpatRaster

  • aspect: Aspect in radians as SpatRaster

  • hillshade: Hillshade as SpatRaster

  • contours: Contour lines as SpatVector

  • streams: Stream network as SpatRaster

  • flow_acc: Flow accumulation as SpatRaster

Details

This function creates a comprehensive terrain visualization by:

  1. Using pre-calculated geomorphology metrics (slope, aspect, hillshade, contours, streams)

  2. Creating a multi-layer visualization with hillshade, slope, contours, and streams

Note

Requires the following packages: terra, whitebox, sf

Examples

if (FALSE) { # \dontrun{
# Load dtm
dtm <- rast("path/to/dtm.tif")

# Calculate metrics once
metrics <- calc_geomorph_metrics(dtm, stream_threshold = 1000)

# Use metrics for plotting
result <- plot_slope_channels(dtm, metrics = metrics)

# Custom parameters
result <- plot_slope_channels(
  dtm = dtm,
  metrics = metrics,
  contour_interval = 20,
  stream_color = "darkblue"
)

# Access individual results
plot(result$slope)
plot(result$streams)
} # }