Hydrological Processes - Drainage Network
The drainage network is defined at the " Computing the Hydrological Grid ".
A threshold value is determined and each cell in the grid is searched. The cell will
be part of the drainage network if the cell value in the accumulated flow grid is
greater or equal the threshold value defined. In this case, the cell value will be
inserted in the same position in the output grid, which will have the drainage network.
Thus, at the end of processing only values greater or equal the threshold value will be
represented in the drainage grid, and in the other cells a default value will be used.
Next, the procedure for computing the drainage network will be presented:
Computing the Drainage Network:
- activate, in the "Control Panel", the numerical information layer
which has the accumulated flow grid;
- click on DTM in the main menu and select Hydrological Processes - Drainage Network ...
to open an associated window;
- click on Output Category... to select
the category for the IL that will be created. The " Categories List" window is presented. By default, only the categories of the numerical model are
presented. After selecting the category, click on Apply in this window;
- set number of bits for the Output grid, the user can choose between 32 or 64 bits;
- give the name for the Output IL which will have the drainage network;
- type in the Threshold Value;
- click on Apply to generate the grid which has the drainage network ...
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