4.6             Catchment Grid

 

All the grids draining to a particular stream polyline element are grouped into one type of catchment grid. Catchment grids are marked according to the stream polyline nomenclature with integer numbers starting with 1.

 

Figure x.x shows the catchment grid obtained for the synthetic grid using Stream and Flow direction grid discussed in section 4.3 and 4.2 respectively. Different colors are used for clear representation of the catchment grid.

 

 

In the Input section of the dialog browse the Link Grid and Flow Direction Grid generated by the step 4.4 and 4.2 respectively. In the Output section of the dialog browse the file name to which the Catchment Grid could be saved. At this point the module is ready to run; select Run to begin processing. Please be patient until it completes processing. The text browser at the bottom of the dialog should provide information related to any error or processing. If the Load in Data Frame is checked the generated Catchment Grid will be automatically loaded in the Qgis window. After the processing is complete you need to press Close to proceed to next step.