Is your directional linear network driving you crazy? These 3 interdependent models will help you find and fix a multitude of problems in your GIS network so that your network analysis (like shortest path) will work flawlessly without the need to use a topology tolerance to compensate for bad data. Basically, it will help you create a perfect line network! It makes a great complement to the topology checker plugin.

Model 1 aims to fix geometries and will:

-a) Find and show to the user all the invalid geometries that need to be fixed before any GIS analysis. (Some geometries must be fixed by the user, and some can be automatically corrected by the model.) An empty output layer means there are no errors found.

-b) Remove duplicate geometries.

-c) Remove duplicate nodes (vertices) (New in version 2).

-d) Find and show to the user all the multipart lines that have been converted to singlepart lines.

You may need to fix the geometries manually and re-run the model until you are happy with the results. Outputs from the first model are fed to model 2.

All models provide a way to track changes when modifications are done to the network file. The only exception to this rule is the deleted duplicate geometries and duplicate nodes of model 1. The original Feature ID is maintained to help the user merge old databases with the new geometries. The original input data is read but never modified.

Visit the project web site at https://gitlab.com/njacadieux/fix-directional-network-qgis-models and read “A Python Algorithm for Shortest-Path River Network Distance Calculations Considering River Flow Direction” for more details https://doi.org/10.3390/data5010008.

Watch my presentation of the model at the QGIS Open Day (2023-02-24) https://www.youtube.com/live/xmxPeAXLTx0?feature=share

Please go to https://plugins.qgis.org/models/ or to https://gitlab.com/njacadieux/fix-directional-network-qgis-models/ to download the models, test data or to file bug reports.

Built and tested on QGIS 3.28.2, seems to work with QGIS 3.22.10 LTR