Channel Network
(c) 2001 by O.Conrad
This module derives a channel network based on gridded digital elevation data.
Use the initiation options to determine under which conditions channels shall start.
Parameters
- Grid system
Grid system
- Grid system
- Elevation
Input Grid
- A grid that contains elevation data.
- Flow Direction
Input Grid
- An optional grid that provides information about flow directions.
Values between 1 to 8 force the flow of a cell to be given to one its adjacent neighbor cells (1->NE, 2->E, 3->SE, 4->S, 5->SW, 6->W, 7->NW, 8->N). In case of other values the algorithm will use its own routing scheme.
This option is in particular useful to supply the algorithm with routes that lead the flow through closed depression.
- Channel Network
Output Grid
- If a cell is part of a channel its value equals the channel order. Otherwise the cell is marked as no-data.
- Channel Direction
Output Grid
- If a cell is part of a channel then its value shows the flow direction of the channel (1->NE, 2->E, 3->SE, 4->S, 5->SW, 6->W, 7->NW, 8->N). Otherwise the cell is marked as no-data.
- Channel Network
Output Shapes
- This shapes layer will contain the resulting channel network in vector format (lines).
- Initiation Grid
Input Grid
- Dependent on the chosen 'Initiation Type' and 'Initiation Threshold' the values of this grid control where a channel is initiated.
- Initiation Type
Choice
- Options:
- Less than
- Equals
- Greater than
Controls under which condition a channel is initiated.
Available choices: Less than, Equals, Greater than
- Initiation Threshold
Floating point
- Dependent on the chosen 'Initiation Grid' and 'Initiation Type' this value controls under which condition a channel is initiated.
- Divergence
Input Grid
- Tracing: Convergence
- Tracing: Max. Divergence
Integer
- Tracing: Stop after x cells with divergent flow
Minimum: 1.0
- Tracing: Weight
Input Grid
- Tracing: Weight
- Min. Segment Length
Integer
- Minimum Segment Length (Cells)