Checking Shape Files in QGIS

There are 3 things which need to be checked when ShapeFiles are received and before forwarding onto the development team:-

1. Check Polygon, attribute table and Projection

2. Check for any missing lines

3. Check for 2D 

1.Check Polygon, attribute table and Projection 

Viewing a .shp file to check

1. Create a new Project, then Layer > Add Layer > Add Vector Layer.  Layer will be visible, and also selectable within Layers box.

Figure 1

Alternatively, from a Mac, right click on a .shp file and open with QGIS.

2. Right click on Layer in 'Layers' and 'Open Attribute table to check polygon names are present and correct (these are the names which will appear at the 'Area' name within the system).  See Figure 2.

These can be edited by clicking on the 'Pencil' icon and updating the column name. See Figure 3.

Figure 3.

3. Check the map layers by selecting Google Maps layers (see step . Add Google Maps layer) to ensure the shape is correctly positioned on the map.

2. Check for any missing lines

Open the Topology Checker Panel (see other for installation instructions).

Ensure you have the correct layer selected in the Layers panel.  Select the Spanner

Then Add rule as below using .shp file which you are checking. Click OK.

3. Check for 2D 

From Layer, right click and select 'Export', then 'Save Features As'.

On the Geometry section check if the 'Include z-dimension' boolean is selected.  If not, there is no further actions.

If the tick is present, you can convert the shape file to 2D by :-

1. Selecting the Geometry Type to 'Polygon' and then unselecting the 'Include z-dimension'.

2. Then entering a File Name and clicking 'OK'.

3. This will generate new shapefiles in 2D and these can be used.

Other

Add Google Maps layer :-

1. Make a new connection, with right click the XYZ Tiles as in figure 4.

2. Give the name, for example: Google Maps.  In the URL copy and paste the Google Maps below. Set the max zoom level to 18. See figure 5.

https://mt1.google.com/vt/lyrs=r&x={x}&y={y}&z={z}

Install Topology Checker plugin :- 

Install topology checker plugin (Menu > Plugins).