I'm using the processing tool named "Network analysis" in order to analyze a sewage network. I'm using the tools "Shortest path" and "Service area". They work fine, but I can’t add blocking points which interrupt the network.

Furthermore, I would like to add criteria considering the piping type (stored in an attribute of the table) (for example only wastewater piping or rainwater piping,…). I know that ArcGIS Pro propose it, but I don’t find any information in it for QGIS.

Is there a way to add these conditions?

  • Unfortunately (yet) there is no such option. But would be a great feature. So far you could only add a speed field to a line and give it the value 0. – MrXsquared Jun 12 '19 at 11:53

I have worked with these processing tools a few times, and don't think there are options to disrupt the network.

A workaround might be breaking the lines somehow. For example you could try to split the feature, which might not work. If you have the blockages as polygons or points (which you could turn to polygons with a small buffer) you could then use 'difference'to remove that space and cut it from the network.

Visually if you do this small enough it won't affect anything you are displaying?

  • I can't split the features to disrupt the network, sorry ! – User Jun 12 '19 at 12:00
  • If you have the blockages as a layer then my method will work, I did a test myself. It might be a bit clunky but could provide a suitable workaround until the feature changes! – DoktorDibbs Jun 12 '19 at 12:05
  • 2
    @User, when you say you can't split the features, do you mean that you are unable to do so, as in you can't figure out how? Or do you mean that you are not allowed, as in breaking the network is not an acceptable solution? – csk Jun 13 '19 at 16:38
  • yes @csk that is what I was wondering too – DoktorDibbs Jun 14 '19 at 12:50
  • We can add a direction field and fix the value at 1 for all the pipelines and when we want to exclude a pipeline, turn its value to 0. – User Jul 19 '19 at 6:47

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