Tool Wind Exposition Index
This tool calculates the average 'Wind Effect Index' for all directions using an angular step. Like the 'Wind Effect Index' it is a dimensionless index. Values below 1 indicate wind shadowed areas whereas values above 1 indicate areas exposed to wind.
References
- Boehner, J., Antonic, O. (2009): Land-surface parameters specific to topo-climatology. In: Hengl, T., Reuter, H. [Eds.]: Geomorphometry - Concepts, Software, Applications. Developments in Soil Science, Volume 33, p.195-226, Elsevier.
- Gerlitz, L., Conrad, O., Böhner, J. (2015): Large scale atmospheric forcing and topographic modification of precipitation rates over High Asia – a neural network based approach. Earth System Dynamics, 6, 1-21. doi:10.5194/esd-6-61-2015..
- Author: J.Boehner, O.Conrad (c) 2015
- Menu: Terrain Analysis|Climate and Weather
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Elevation | Grid, input | DEM | - | - |
| Output | Wind Exposition | Grid, output | EXPOSITION | - | - |
| Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Search Distance [km] | Floating point | MAXDIST | - | Minimum: 0.000000
Default: 300.000000 |
| Angular Step Size (Degree) | Floating point | STEP | - | Minimum: 1.000000
Maximum: 45.000000
Default: 15.000000 |
| Old Version | Boolean | OLDVER | use old version for constant wind direction (no acceleration and averaging option) | Default: 0 |
| Acceleration | Floating point | ACCEL | - | Minimum: 1.000000
Default: 1.500000 |
| Elevation Averaging | Boolean | PYRAMIDS | use more averaged elevations when looking at increasing distances | Default: 0 |
Command-line
Usage: saga_cmd ta_morphometry 27 [-DEM <str>] [-EXPOSITION <str>] [-MAXDIST <double>] [-STEP <double>] [-OLDVER <str>] [-ACCEL <double>] [-PYRAMIDS <str>]
-DEM:<str> Elevation
Grid, input
-EXPOSITION:<str> Wind Exposition
Grid, output
-MAXDIST:<double> Search Distance [km]
Floating point
Minimum: 0.000000
Default: 300.000000
-STEP:<double> Angular Step Size (Degree)
Floating point
Minimum: 1.000000
Maximum: 45.000000
Default: 15.000000
-OLDVER:<str> Old Version
Boolean
Default: 0
-ACCEL:<double> Acceleration
Floating point
Minimum: 1.000000
Default: 1.500000
-PYRAMIDS:<str> Elevation Averaging
Boolean
Default: 0