Data from Stats Can
We wish to get data from Stats Can that shows incidence of low income for the Fraser Fort George area. The search should look something like the clickable image below (don’t forget the DAUID though):
Bring the table into Excel and clean it up as usual. What do yo notice about one of the data records (rows) in regards to its numerical value? If you are struggling with getting the data into excel, there is a clean version called incidence_low_income.xls in N:\labs\geog204\health_tutorial. Make sure it is the xls (or xlsx) version not the csv (how can you make sure?).
Open up QGIS and load the layer da_pg_pop (from the same directory) into your project (the projection is UTM Zone 10N – 26910). Once it is open, locate the DAUID that matches the row that has the value of “n/a” from the data pulled down from Stats Can. Why do you think this DA has the “n/a” value (perhaps you should look at it in QGIS)?
The layer we are working with is a data layer provided by Jolene Jackson. She is the student that did the GIS work for Neil in the summer of 2008. Can you notice anything different about this layer in contrast to the DA layers we have worked with so far? Take a look at the dabc_2006 layer in n:\labs\geog204\project_data\dabc\2006 to see the difference – if you wish (remember it is in a Lat Lon projection). Did you find the “n/a” DAUID in this layer?
Lets keep using the layer from Jolene. To make a copy of the file in you own directory – save it to a shape file called da_pg in a directory called n:\yourusername\geog204\health_tutorial (should you write down how you did this?). Keep the layer from Jolene and colour it with a light green colour.
Now take the data you obtained from stats can into Quantum. There is a comma separated value file (csv) in the N:\labs\geog204\health_tutorial directory called incidence_low_income.csv that you can use if your data clean up in Excel is not going well. Join this imported table with the table from your newly saved shape file. Make a colour map showing the incidence of low income – try higher incidences in red moving to lower incidences through oranges and yellows. Follow along with Scott to see how you can do this.
Data Hint: The csv table loaded above had a csvt file associated with it – can you remember why there is an accompanying file? Open it in a text editor to see its significance.
Calculating Values to set occurrence values
Load the layer low_income_incidence_percent from the N:\labs\geog204\health_tutorial directory into your project. Use uniques value to create a map with the Low_income column values. What has Jolene done here? Do you think that she derived her incidence percentage values differently than we did? What is the cut off percentage she is using in order to give an occurrence value of “1″.?
Lets use the data we have in our da_pg_pop layer to do the same thing that Jolene did, but lets create our binary values (either 0 or 1) for both the incidence of low income percentages as well as for the rate of unemployment and percentage of earned and government support income. We will do this by:
- adding the employments rates csv file in the health_tutorial directory.
- joining the tables we wish to use from all the csv files
- save the new joined file as a new shape file
- create ranked values for the census stats
- sum up the ranks into an index for mapping
How is you table manipulation skills coming along?
Jolene and Neil used actual income values for DAs to create their percentages (instead of downloading the incidence directly from Stats Can). These percentages were based on values for Prince George only. We do not have enough time to do so today – but can you think of how this can be done – either in Quantum or Excel?
As this is a short tutorial today, we will hold off on looking at the spatial distribution of the population or house holds of indexed DA layers for Prince George. Can you think of how we could use Block, Postal Code or Building layers to clarify population distribution?