Tool Valley Depth
Valley depth is calculated as difference between the elevation and an interpolated ridge level. Ridge level interpolation uses the algorithm implemented in the 'Vertical Distance to Channel Network' tool. It performs the following steps:
- Definition of ridge cells (using Strahler order on the inverted DEM).
- Interpolation of the ridge level.
- Subtraction of the original elevations from the ridge level.
- Author: O.Conrad (c) 2012
- Menu: Terrain Analysis|Channels
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Elevation | Grid, input | ELEVATION | - | - |
| Output | Valley Depth | Grid, output | VALLEY_DEPTH | - | - |
| Ridge Level (*) | Grid, output, optional | RIDGE_LEVEL | - | - |
| Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Tension Threshold | Floating point | THRESHOLD | Maximum change in elevation units (e.g. meter), iteration is stopped once maximum change reaches this threshold. | Minimum: 0.000000
Default: 1.000000 |
| Maximum Iterations | Integer | MAXITER | Maximum number of iterations, ignored if set to zero | Minimum: 0
Default: 0 |
| Keep Ridge Level above Surface | Boolean | NOUNDERGROUND | - | Default: 1 |
| Ridge Detection Threshold | Integer | ORDER | - | Minimum: 1
Maximum: 7
Default: 4 |
| (*) optional |
Command-line
Usage: saga_cmd ta_channels 7 [-ELEVATION <str>] [-VALLEY_DEPTH <str>] [-RIDGE_LEVEL <str>] [-THRESHOLD <double>] [-MAXITER <num>] [-NOUNDERGROUND <str>] [-ORDER <num>]
-ELEVATION:<str> Elevation
Grid, input
-VALLEY_DEPTH:<str> Valley Depth
Grid, output
-RIDGE_LEVEL:<str> Ridge Level
Grid, output, optional
-THRESHOLD:<double> Tension Threshold
Floating point
Minimum: 0.000000
Default: 1.000000
-MAXITER:<num> Maximum Iterations
Integer
Minimum: 0
Default: 0
-NOUNDERGROUND:<str> Keep Ridge Level above Surface
Boolean
Default: 1
-ORDER:<num> Ridge Detection Threshold
Integer
Minimum: 1
Maximum: 7
Default: 4