At the moment I do this manually:

  1. open a shapefile
  2. open the attribute table
  3. use "select features using an expression" - the expression is "area" < 200
    1. then I use vector/geoprocessing tools/eliminate sliver polygons
    2. I select "common boundary", add a name and location for a new shapefile.

I have tried to automate this process using the modeller, but even after looking at some tutorials I could not achieve this.

Since I have many shapefiles, I would like to process them one at the time automatically. Note that the resulting shapefile should have the original shapefile name with a prefix or a suffix - I don't mind which.

After spending some time with QGIS, I had a look at the "Processing Toolbox" and I have tried "Eliminate Sliver Polygon" as a Batch Process. It seems like it should do what I am looking for - but I guess that my parameters are not correct and reading the help file did not help me. There are three entries that I have to fill in:

  • Selection Attribute
  • Comparison
  • Value

In "selection attribute" I have tried "AREA" (with and without quotes), but is this the correct parameter?

  • I don't see a real question. You want someone to write a program for you? Please see the Help for gis.stackexchange.com/help/how-to-ask – Brad Nesom May 19 '15 at 12:55
  • No, I don;t want someone to write a program. I want to know how to automate a process within QGIS using a GUI. I have edited my question - hopefully it will be more clear – user52354 May 19 '15 at 15:29

At the end I did not have to use the QGIS Modeler, even if probably its implementation would be more efficient of my solution.

I have used "Eliminate Sliver Polygon" from the "Processing Toolbox" as a "Batch Process". I have selected all my shape files, then manually filled in: Selection Attribute: name of the field in my table, in uppercase, no quotes; Comparison: selected from dropdown list; Value: entered the value without any quotes;

I then used the autofill option to enter a name for amended shap files.

This method is much quicker then running the same process for each layer/file manually. It could be improved if some parameters (Selection attribute, comparison and value) could be filled automatically or for multiple entries at once (not each at the time).


The Qgis Modeler isn't near as good as the ArcGis equivalent. If you want to stay with Qgis // opensource. You should really start using python//pyqgis

Follow this link to Pyqgis

And in your case it isn't that complicated : a loop over all your layers, an applying 2 operations is all you need.

Here is a hint : To get hold of all your layers :


  • Ok, but is it "impossible" to do what I want with the Modeler or just more cumbersome? I am not a programmer and reading about Python is like reading a foreign language for me. – user52354 May 19 '15 at 13:53

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