Tutorial: Delineate Multiple Subcatchments

3. Snap pour points

We can only delineate (sub)catchments if the pour points are on the delineated hydrography, otherwise there's no river according to your model. We can achieve that by snapping the pour points to the hydrography layer.

1. Open the Processing Toolbox. In the main menu go to  Processing | Toolbox to open the Processing Toolbox panel.

2. In the Processing Toolbox choose Vector geometry | Snap geometries to layer.

3. In the Snap Geometries to Layer dialogue choose Pour point as Input layer and Rur hydrography as Reference layer. Change the Tolerance to 100 m. This is the search radius for snapping the point to the line. Change Behavior to Prefer closest point, insert extra vertices where required. You can play with this setting if the results are okay. Save the Snapped geometry to the project GeoPackage with the layer name Snapped pour points.

4. Click Run and Close the dialogue after processing.

5. Check the result.

Now we've snapped the pour points we can proceed with delineating their catchments in the next section.