Looking at Boundary Files
We will look a the differences and relationships between the different Stats Can Boundary layers later on (in Tutorial and in Lecture) , but for now let’s have a look at the two types of DA boundary files we are using in the course.
Open up QGIS and load the two data base layers from the tut4 folder in the lab data for geog204 (/home/labs/geog204/tut4):
Look at the two layers – what are the differences between them? Have a peak a the following web pages:
Notice the comments regarding the treatment of water bodies in the digital boundary files.
Zoom into the area around Prince George. Do the two layers differ – how?
Load on the 2001 DA cartographic layer from the same folder. How does this layer differ from the other two? What differences are there in the attribute table for this layer?
Sort the table on the DAUID value for the 2001 layer. What do we notice about how unique these values are. Highlight the 59590002 values and zoom to the selected.
Why are there five polygons with the same DAUID?
What are the DAUID Values for the 2006 layers under the largest 2001 polygon with the value of 59590002 for its DAUID?
Zoom into Prince George and look a the differences between the layers – how does water fit into the different years?
Query the value 59530037 in the attribute table for the 2001 layer
Can you see where we wold have some pretty bizarre results for population densities or population totals if we were using the 2001 data for our calculations?
How does this set of polygons differ from the 2006 data sets?
Load the stats_can_lakes_rivers_2006.shp layer into your project your project
How do the polygons on this layer compare with those water bodies around Prince George?
Where do we go from here?
You may recall from the slides Neal Hanlon created that the DA layers are supposed to be consistent between years. Based on what we have seen so far how well with this work?
Scott has downloaded the digital and cartographic files for 2011 as well. You are welcome to compare the 2011 data to the 2001 and 2006 data. The 2016 boundary files are also available in the /home/labs//geog204/boundary_files/2016 folder for use in comparing boundary alignment.