Module Catchment Area (Flow Tracing)
Flow tracing algorithms for calculations of flow accumulation and related parameters. These algorithms trace the flow of each cell in a DEM separately until it finally leaves the DEM or ends in a sink.
References:
Rho 8 (this implementation adopted the original algorithm only for the flow routing and will give quite different results):
- Fairfield, J. / Leymarie, P. (1991):
'Drainage networks from grid digital elevation models',
Water Resources Research, 27:709-717
Kinematic Routing Algorithm:
- Lea, N.L. (1992):
'An aspect driven kinematic routing algorithm',
in: Parsons, A.J., Abrahams, A.D. (Eds.), 'Overland Flow: hydraulics and erosion mechanics', London, 147-175
DEMON:
- Costa-Cabral, M. / Burges, S.J. (1994):
'Digital Elevation Model Networks (DEMON): a model of flow over hillslopes for computation of contributing and dispersal areas',
Water Resources Research, 30:1681-1692
- Author: O.Conrad (c) 2001
- Specification: grid
- Menu: Terrain Analysis|Hydrology|Catchment Area
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Elevation | Grid (input) | ELEVATION | - | - |
| Sink Routes (*) | Grid (optional input) | SINKROUTE | - | - |
| Weight (*) | Grid (optional input) | WEIGHT | - | - |
| Input for Mean over Catchment Calculation (*) | Grid (optional input) | VAL_INPUT | - | - |
| Material (*) | Grid (optional input) | MATERIAL | - | - |
| Accumulation Target (*) | Grid (optional input) | TARGET | - | - |
| Output | Catchment Area | Grid (output) | CAREA | - | - |
| Mean over Catchment | Grid (output) | VAL_MEAN | - | - |
| Total accumulated Material (*) | Grid (optional output) | ACCU_TOT | - | - |
| Accumulated Material from Left Side (*) | Grid (optional output) | ACCU_LEFT | - | - |
| Accumulated Material from Right Side (*) | Grid (optional output) | ACCU_RIGHT | - | - |
| Options | Step | Integer | STEP | - | Minimum: 1
Default: 1 |
| Method | Choice | METHOD | - | Available Choices:
[0] Rho 8
[1] Kinematic Routing Algorithm
[2] DEMON
Default: 1 |
| DEMON - Min. DQV | Floating point | MINDQV | DEMON - Minium Drainage Quota Volume (DQV) for traced flow tubes | Minimum: 0.000000
Maximum: 1.000000
Default: 0.000000 |
| Flow Correction | Boolean | CORRECT | - | Default: 0 |
| (*) optional |
Command-line
Usage: saga_cmd ta_hydrology 2 -ELEVATION <str> [-SINKROUTE <str>] [-WEIGHT <str>] [-CAREA <str>] [-VAL_INPUT <str>] [-VAL_MEAN <str>] [-MATERIAL <str>] [-TARGET <str>] [-ACCU_TOT <str>] [-ACCU_LEFT <str>] [-ACCU_RIGHT <str>] [-STEP <num>] [-METHOD <str>] [-MINDQV <str>] [-CORRECT <str>]
-ELEVATION:<str> Elevation
Grid (input)
-SINKROUTE:<str> Sink Routes
Grid (optional input)
-WEIGHT:<str> Weight
Grid (optional input)
-CAREA:<str> Catchment Area
Grid (output)
-VAL_INPUT:<str> Input for Mean over Catchment Calculation
Grid (optional input)
-VAL_MEAN:<str> Mean over Catchment
Grid (output)
-MATERIAL:<str> Material
Grid (optional input)
-TARGET:<str> Accumulation Target
Grid (optional input)
-ACCU_TOT:<str> Total accumulated Material
Grid (optional output)
-ACCU_LEFT:<str> Accumulated Material from Left Side
Grid (optional output)
-ACCU_RIGHT:<str> Accumulated Material from Right Side
Grid (optional output)
-STEP:<num> Step
Integer
Minimum: 1
Default: 1
-METHOD:<str> Method
Choice
Available Choices:
[0] Rho 8
[1] Kinematic Routing Algorithm
[2] DEMON
Default: 1
-MINDQV:<str> DEMON - Min. DQV
Floating point
Minimum: 0.000000
Maximum: 1.000000
Default: 0.000000
-CORRECT:<str> Flow Correction
Boolean
Default: 0