Module TOBIA
This module computes both a continuous and a categorical TOBIA (Topography Bedding Intersection Angle) Index according to Meentemeyer & Moody (2000) For computation, a slope and a aspect raster (both in radians) determining slope face orientations are required. The categorical TOBIA classifies the alignement of a geological structure to Topography into seven classes:
0) Underdip slope
1) Dip slope
2) Overdip slope
3) Steepened escarpmemt
4) Normal escarpment
5) Subdued escarpment
6) Orthoclinal slope
The continuous TOBIA index ranges from -1 to 1 (parallel orientation)
The structure TOBIA should be calculated with can be set either distributed (through dip direction and dip grids, in degrees!), or globally using integers (dip and dip direction, in degrees!). The module creates a TOBIA class integer grid, and (optionally) a continuous TOBIA index grid.
Reference: Meentemeyer R. K., Moody A. (2000). Automated mapping of conformity between topographic and geological surfaces. Computers & Geosciences, 26, 815 - 829.
- Author: A. Günther (c) 2012
- Specification: grid
- Menu: Terrain Analysis|Slope Stability
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Slope grid (rad) | Grid (input) | A | - | - |
| Aspect grid (rad) | Grid (input) | B | - | - |
| Dip grid (degrees) (*) | Grid (optional input) | C | A grid representing the dip of the structure plane (in degrees) | - |
| Dip direction grid (degrees) (*) | Grid (optional input) | D | A grid representing the dip direction of the structure plane (in degrees) | - |
| Output | TOBIA classes | Grid (output) | E | Resulting TOBIA classses (1-7) grid | - |
| TOBIA index (*) | Grid (optional output) | F | Resulting TOBIA index (-) grid | - |
| Options | Global structure dip (degrees) | Floating point | fB | Constant value if no raster set | Default: 45.000000 |
| Global structure dip direction (degrees) | Floating point | fC | Constant value if no raster set | Default: 90.000000 |
| (*) optional |
Command-line
Usage: saga_cmd ta_slope_stability 1 -A <str> -B <str> [-C <str>] [-D <str>] [-fB <str>] [-fC <str>] [-E <str>] [-F <str>]
-A:<str> Slope grid (rad)
Grid (input)
-B:<str> Aspect grid (rad)
Grid (input)
-C:<str> Dip grid (degrees)
Grid (optional input)
-D:<str> Dip direction grid (degrees)
Grid (optional input)
-fB:<str> Global structure dip (degrees)
Floating point
Default: 45.000000
-fC:<str> Global structure dip direction (degrees)
Floating point
Default: 90.000000
-E:<str> TOBIA classes
Grid (output)
-F:<str> TOBIA index
Grid (optional output)