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I'm looking for help getting the correct shapefile.

I'm working off of the files provided by the canadian government at http://geobase.ca/geobase/en/search.do?identifiant=&region=mb&produit=nhn&language=en

These are identified as all the shapefiles that touch inside the Manitoba border. I've joined these files together and am attempting to clip them by another shapefile we have of the Manitoba border (Another tech created this by getting the entire Canadian border and cutting it down)

My issue is, every time I clip it, the file returned always appears to be blank, despite the lengthy time it takes to create the file. I'm entering the input layer as the water layer, and the clipping layer as the border layer.

We are working out of QGIS. I personally have little to no GIS training.

Also I should note that I have made sure that the CRS match and I've also fixed all validity errors.

PolyGeo
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user3499144
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  • http://gis.stackexchange.com/questions/37226/how-to-crop-shapefiles-in-qgis?rq=1 looks like it might answer your question. – nmtoken Apr 04 '14 at 18:33
  • Did you get a chance to those layers for invalid features. Vector > Geometry tools > Check geometry validity - any invalid features can cause those features to be excluded from results. – SaultDon Apr 04 '14 at 18:44
  • The validity has been all checked. I had to make a couple edits. This bothers me since the data is straight from the Canadian government, I'm confused why there would be errors like that. – user3499144 Apr 04 '14 at 18:49
  • Also, looking at that last post, this is for sure what I needed to start, but I'm past this point now and have been using the clip tool in qgis, but its spitting out what appears to be an empty file – user3499144 Apr 04 '14 at 18:50
  • Most likely a CRS issue. Can you share direct links to two files which exhibit the problem? – underdark Apr 05 '14 at 19:36
  • Do the shapes still match if you turn On-the-fly-reprojection OFF? – AndreJ Apr 07 '14 at 11:56

2 Answers2

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Try building some "new" data by using the Vector|Buffer command and build an 0.1 (10 cm if your crs is UTM metric metres) border around the old. This creates a new shapefile in that process. This fixed some persistant geometry errors once for me. Will also be an implicit way to check the crs.

Willy
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http://mli2.gov.mb.ca//index.html had Manitoba Shape Files that were already in the CRS that I needed and I've been able to complete the project. Thanks for all help provided.

Issue was likely with the CRS, although I had followed a guide on switching it over (not that it was an overly complicated process)

user3499144
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    "switching it over" sounds that you only used Set CRS for Layer, which is definitely wrong here. You have to use Save As ... and select different file name and CRS to get it right. – AndreJ Apr 08 '14 at 04:16