Tool Name	Slope Length
Tool ID	7
Library ID	ta_hydrology
Version	1.0
Author(s)	V.Olaya (c) 2004

Description

The tool allows one to calculate a special version of slope (or flowpath) length. In a first processing step, the slope of each cell is calculated with the method of Zevenbergen & Thorne (1986). The slope length values are then accumulated downslope using the Deterministic 8 (D8) single flow direction algorithm and a threshold criterion: the slope length is only accumulated downslope if the slope of the receiving cell is steeper than half of the slope of the contributing cell (i.e. the accumulation stops if the slope profile gets abruptly flatter).
If several cells are contributing to a cell, the maximum of the accumulated slope length values found in these cells is passed to the receiving cell and then routed further downslope.

Parameters

Name	Type	Identifier	Description
Input
Elevation	grid, input	DEM	The digital elevation model.
Output
Slope Length	grid, output	LENGTH	The maximum slope (flowpath) length.