Drainage Network Extraction

The Drainage Network Extraction operation extracts a basic drainage network (boolean raster map).

As input is required: the output raster map of the Flow Accumulation operation.

You can choose to use as additional input:

• a threshold value, to set a minimum for the number of pixels that should drain into a pixel that is examined;
• a threshold raster map, where pixels can have a threshold value based on e.g. their geological unit or height values;
• when using a threshold map, also the output map of a previous Flow Direction operation is required.

When using a threshold map, the operation will furthermore fill possible gaps between drainage lines.

The output raster map will show the basic drainage as pixels with value True, while other pixels have value False.