D8 Distance To Streams

Description

Computes the horizontal distance to stream for each grid cell, moving downslope according to the D8 flow model, until a stream grid cell is encountered.

Parameters

D8 Flow Direction Grid [raster]
This input is a grid of flow directions that are encoded using the D8 method where all flow from a cells goes to a single neighboring cell in the direction of steepest descent. This grid can be obtained as the output of the “D8 Flow Directions” tool.
Stream Raster Grid [raster]
A grid indicating streams. Such a grid can be created by several of the tools in the “Stream Network Analysis” toolset. However, the tools in the “Stream Network Analysis” toolset only create grids with a value of 0 for no stream, or 1 for stream cells. This tool can also accept grids with values greater than 1, which can be used in conjunction with the Threshold parameter to determine the location of streams. This allows Contributing Area grids to be used to define streams as well as the normal Stream Raster grids. This grid expects integer (long integer) values and any non-integer values will be truncated to an integer before being evaluated.
Threshold [number]

This value acts as threshold on the Stream Raster Grid to determine the location of streams. Cells with a Stream Raster Grid value greater than or equal to the Threshold value are interpreted as streams.

Default: 50

Outputs

Output Distance to Streams [raster]
A grid giving the horizontal distance along the flow path as defined by the D8 Flow Directions Grid to the streams in the Stream Raster Grid.

Console usage

processing.runalg('taudem:d8distancetostreams', -p, -src, -thresh, -dist)

See also