Flow Accumulation (Flow Tracing)
- Author: O.Conrad (c) 2001
- Menu: Terrain Analysis | Hydrology | Flow Accumulation | Alternatives
Description
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. The Rho 8 implementation (Fairfield & Leymarie 1991) adopts the original algorithm only for the flow routing and will give quite different results.
References
- 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. doi:10.1029/93WR03512.
- Fairfield, J. & Leymarie, P. (1991): Drainage networks from grid digital elevation models. Water Resources Research, 27:709-717. doi:10.1029/90WR02658.
- 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. doi:10.1201/b12648.
Parameters
| Name | Type | Identifier | Description | Constraints | |
|---|---|---|---|---|---|
| Input | Elevation | grid, input | ELEVATION | - | - |
| Sink Routes | grid, input, optional | SINKROUTE | - | - | |
| Weights | grid, input, optional | WEIGHTS | - | - | |
| Input for Mean over Catchment | grid, input, optional | VAL_INPUT | - | - | |
| Material for Accumulation | grid, input, optional | ACCU_MATERIAL | - | - | |
| Accumulation Target | grid, input | ACCU_TARGET | - | - | |
| Output | Flow Accumulation | grid, output | FLOW | - | - |
| Mean over Catchment | grid, output | VAL_MEAN | - | - | |
| Accumulated Material | grid, output, optional | ACCU_TOTAL | - | - | |
| Accumulated Material (Left Side) | grid, output, optional | ACCU_LEFT | - | - | |
| Accumulated Material (Right Side) | grid, output, optional | ACCU_RIGHT | - | - | |
| Options | Grid System | grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Step | integer number | STEP | For testing purposes. Only generate flow at cells with step distance (each step row/column). | Minimum: 1 Default: 1 | |
| Flow Accumulation Unit | choice | FLOW_UNIT | - | Available Choices: [0] number of cells [1] cell area Default: 1 | |
| Method | choice | METHOD | - | Available Choices: [0] Rho 8 [1] Kinematic Routing Algorithm [2] DEMON Default: 1 | |
| Flow Correction | boolean | CORRECT | - | Default: 1 | |
| Minimum DQV | floating point number | MINDQV | DEMON - Minimum Drainage Quota Volume (DQV) for traced flow tubes | Minimum: 0.000000 Maximum: 1.000000 Default: 0.000000 |
Command Line
Usage: saga_cmd ta_hydrology 2 [-ELEVATION] [-SINKROUTE ] [-WEIGHTS ] [-FLOW ] [-VAL_INPUT ] [-VAL_MEAN ] [-ACCU_MATERIAL ] [-ACCU_TARGET ] [-ACCU_TOTAL ] [-ACCU_LEFT ] [-ACCU_RIGHT ] [-STEP ] [-FLOW_UNIT ] [-METHOD ] [-CORRECT ] [-MINDQV ] -ELEVATION: Elevation grid, input -SINKROUTE: Sink Routes grid, input, optional -WEIGHTS: Weights grid, input, optional -FLOW: Flow Accumulation grid, output -VAL_INPUT: Input for Mean over Catchment grid, input, optional -VAL_MEAN: Mean over Catchment grid, output -ACCU_MATERIAL: Material for Accumulation grid, input, optional -ACCU_TARGET: Accumulation Target grid, input -ACCU_TOTAL: Accumulated Material grid, output, optional -ACCU_LEFT: Accumulated Material (Left Side) grid, output, optional -ACCU_RIGHT: Accumulated Material (Right Side) grid, output, optional -STEP: Step integer number Minimum: 1 Default: 1 -FLOW_UNIT: Flow Accumulation Unit choice Available Choices: [0] number of cells [1] cell area Default: 1 -METHOD: Method choice Available Choices: [0] Rho 8 [1] Kinematic Routing Algorithm [2] DEMON Default: 1 -CORRECT: Flow Correction boolean Default: 1 -MINDQV: Minimum DQV floating point number Minimum: 0.000000 Maximum: 1.000000 Default: 0.000000