Module Valley and Ridge Detection (Top Hat Approach)
Calculating fuzzy valley and ridge class memberships using the Top Hat approach. Based on the AML script 'tophat' by Jochen Schmidt, Landcare Research.
References:
Rodriguez, F., Maire, E., Courjault-Rad'e, P., Darrozes, J. (2002): The Black Top Hat function applied to a DEM: a tool to estimate recent incision in a mountainous watershed. (Estib`ere Watershed, Central Pyrenees). Geophysical Research Letters, 29(6), 9-1 - 9-4.
- Author: O.Conrad (c) 2013
- Specification: grid
- Menu: Terrain Analysis|Terrain Classification
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Elevation | Grid (input) | DEM | - | - |
| Output | Valley Depth (*) | Grid (optional output) | VALLEY | - | - |
| Hill Height (*) | Grid (optional output) | HILL | - | - |
| Valley Index | Grid (output) | VALLEY_IDX | - | - |
| Hill Index | Grid (output) | HILL_IDX | - | - |
| Hillslope Index (*) | Grid (optional output) | SLOPE_IDX | - | - |
| Options | Valley Radius | Floating point | RADIUS_VALLEY | radius given in map units used to fill valleys | Minimum: 0.000000
Default: 1000.000000 |
| Hill Radius | Floating point | RADIUS_HILL | radius given in map units used to cut hills | Minimum: 0.000000
Default: 1000.000000 |
| Elevation Threshold | Floating point | THRESHOLD | elevation threshold used to identify hills/valleys | Minimum: 0.000000
Default: 100.000000 |
| Slope Index | Choice | METHOD | - | Available Choices:
[0] default
[1] alternative
Default: 0 |
| (*) optional |
Command-line
Usage: saga_cmd ta_morphometry 24 -DEM <str> [-VALLEY <str>] [-HILL <str>] [-VALLEY_IDX <str>] [-HILL_IDX <str>] [-SLOPE_IDX <str>] [-RADIUS_VALLEY <str>] [-RADIUS_HILL <str>] [-THRESHOLD <str>] [-METHOD <str>]
-DEM:<str> Elevation
Grid (input)
-VALLEY:<str> Valley Depth
Grid (optional output)
-HILL:<str> Hill Height
Grid (optional output)
-VALLEY_IDX:<str> Valley Index
Grid (output)
-HILL_IDX:<str> Hill Index
Grid (output)
-SLOPE_IDX:<str> Hillslope Index
Grid (optional output)
-RADIUS_VALLEY:<str> Valley Radius
Floating point
Minimum: 0.000000
Default: 1000.000000
-RADIUS_HILL:<str> Hill Radius
Floating point
Minimum: 0.000000
Default: 1000.000000
-THRESHOLD:<str> Elevation Threshold
Floating point
Minimum: 0.000000
Default: 100.000000
-METHOD:<str> Slope Index
Choice
Available Choices:
[0] default
[1] alternative
Default: 0