Central Baptist Theological Seminary of Minneapolis Skill development

GEOG 360: GIS & MappingInstructions:
1. Set up the lab.
a. Download the Lab 4 Data folder from Canvas. Remember to unzip it and save it
to a designated folder for your class GIS work.
b. Open QGIS.
c. Save your file (to the folder you designated for your class GIS work).
2. Let’s add some data.
a. We’ll start with the Countries shapefile. Add it to your map and open the
attribute table.
b. Below is some metadata you’ll find useful:
Name
ISOCode
EstPop
EstGDP
TotalGHG
Emis2019
Cumulative
CBCO2
Name of country or geographic entity
International Organization for Standardization official
administrative code
Estimated Population (2017)
Estimated Gross Domestic Product (2016)
Total Greenhouse Gas emissions from carbon dioxide
(CO2), methane, nitrous oxide, and F-gases (2016), all
summed up and measured in metric tons of carbondioxide equivalents where ‘equivalent’ means “having
the same warming effect as CO2 over a period of 100
years, includes emissions from land use change (which
can be positive or negative)
Carbon dioxide (CO2) emissions from the burning of fossil
fuels and cement production (2019), excludes land use
change, measured in metric tons
Cumulative CO2 emissions (1751-2018), measured as the total
sum of CO2 emissions produced from fossil fuels and cement,
measured in metric tons
Annual consumption-based CO2 emissions (2018),
measured in metric tons of CO2 per year (includes
emissions caused abroad by the production of imported
goods, excludes emissions caused in the production of
goods that were exported to another country)
GEOG 360: GIS & Mapping
CO2Trade
Share
CO2 emissions embedded in trade (2018), measured as
the net import-export balance in metric tons of CO2 per
year (positive values represent net importers of CO2;
negative values represent net exporters of CO2)
Share of CO2 emissions embedded in trade (2018),
measured in emissions exported or imported as the
percentage of domestic product emissions (positive
values represent net importers of CO2; negative values
represent net exporters of CO2)
Partppm
Mean annual exposure to particulate matter less than 2.5
microns in aerodynamic diameter, measured in micrograms
per cubic meter
Share
Share of CO2 emissions embedded in trade (2018),
measured in emissions exported or imported as the
percentage of domestic product emissions (positive
values represent net importers of CO2; negative values
represent net exporters of CO2)
c. Consider what we have in terms of data. Note that there are some Null values
(we will examine what to do with those later). When you are done, close the
attribute table and return to the map view.
3. Since this lab is about projection, let’s examine what projection this data is in.
a. First let’s see the projection the data is stored in. Remember that data can be
stored and displayed in different projections.
b. Right click on the Countries shapefile in your Layers panel and select Properties.
c. So far we have primarily been using the Symbology tab. This time, let’s select
the Information tab (all the way at the top). In the “Information from provider”
section, you can see the CRS that the data is stored in. For this layer, you should
see “EPSG: 4326 – WGS 84 – Geographic.” This means that this shapefile is
stored in a geographic coordinate system with the datum WGS 84. What does
the EPSG: 4326 part mean? Well the EPSG registry is a public registry of
coordinate reference systems, so the WGS 84 datum based geographic
coordinate system is stored in that registry under the number 4326. Once
you’ve found the CRS, go ahead and hit Cancel to close the Properties window.
d. Now, let’s see what happens if we have the wrong geographic coordinate system
recorded. For this step, I would recommend making a copy of our layer so that
we can play with the CRS without messing up our original data. Now, remember
GEOG 360: GIS & Mapping
that QGIS only links data when we add it to our map, so we don’t just want to
add a second copy or duplicate of this same shapefile. Instead, we want to
export the layer, giving it a new name (this is sort of like Saving As in a word
document), and adding it back to your map. To do this, right click on the
Countries layer and select Export → Save Features As. Click on the “…” button at
the end of the File name line (don’t just give it a name as you first need to tell
the program where to save the new file you are making). Using that “…” button,
save your new file to your class GIS folder (be sure to give it a name that tells you
that this is a temporary or scratch layer as we will be intentionally messing it up
and don’t want to confuse it with our good layer), make sure that the “Add saved
file to map” box at the bottom of the pop-up window is checked, and then click
OK.
e. You should see your new layer appear in the Layers panel. We will be working
form this layer, for the next couple of steps.
f. Go ahead and right click on your new copy, select Properties, and then this time,
we want to click on the Source tab. Here we can see under “Assigned
Coordinate Reference System (CRS)” that the program has identified the CRS as
the WGS 84 CRS we saw in the Information tab.
g. For illustration purposes, go ahead click on the CRS button at the end of the line
(a globe with a cone on top). This will open a pop-up window. Type “Mercator”
into the Filter box and then select a Mercator projection from the options below
(it doesn’t matter which one, since we are just doing this to demonstrate why
recording the correct CRS is important). Once you have selected a Mercator
projection, click OK and then OK again.
h. Now, it will likely look like that layer has simply disappeared from your map, but
it is actually still there, just on a totally different scale from your actual CRS such
that the whole world fits in a little dot centered around the coordinates 0,0. To
find it, right click on the layer you changed and select “Zoom to Layer.” You
should see the layer you changed appear.
i.
Now use the zoom out tool (the magnifying glass with the – on it) and click in the
center of your map until you can see your other map appear (this should take
about 10-15 clicks). What we see is that while both of these are centered
around 0 degrees latitude and 0 degrees longitude, they are on such different
scales that we can’t even see them both at the same time since we gave the
program incorrect information about the CRS the data was stored in.
j.
Since that was just for demonstration purposes, let’s go ahead and remove the
layer we created and have been playing around with by right clicking on it and
GEOG 360: GIS & Mapping
selecting Remove Layer. If you want to go into your GIS folder and delete it, you
can, but you don’t have to.
4. Now let’s learn how to change the coordinate system of your map view window.
a. First, let’s add a basemap so that we can see the type of changes we will get. To
do this, scroll in your Browser panel down to XYZ Tiles and add OpenStreetMap
to your map. It will appear on top of your existing layer, so in the Layer panel,
click and drag it below your Countries shapefile.
b. We can find the map’s coordinate system by clicking on the “Current CRS”
button in the lower right-hand corner of the screen. It should have a picture of a
globe with a cone over it and the name of the CRS that the map is currently in. If
you have followed the instructions so far, it should say “EPSG: 4326.”
c. When you click on the “Current CRS” button you’ll get a pop-up window where
you can change the CRS to anything you like. Let’s start by changing it to a
Mercator projection so that we can see how this differs from changing the data
CRS. Go ahead and type “Mercator” into the Filter box and select a Mercator
projection. Click OK and see how your map has changed.
d. Notice that both the countries and the basemap layers changed together and we
are now seeing a different view of the world.
e. Let’s do it again, this time choosing a Sinusoidal projection. Notice how your
map has changed. Also notice how our basemap has white streaks through it—
that is evidence of how the map has been distorted. Go ahead and turn off the
basemap and we will proceed with just our Countries layer. If you want to
remove the OpenStreetMap layer from your Layers panel, feel free.
f. Take a few minutes to play around with the different projections. Pick one you
like the look of.
5. So, now let’s consider our data.
a. Let’s start by exploring the question of how CO2 emissions are distributed
globally. Use Jenk’s natural breaks and 5 classes to map the 2019 CO2 emissions
of each country.
b. Now, remember that we had some Null values in our table, so let’s consider
what to do about that. We want to have a layer that appears as “No Data” in our
legend, so let’s go ahead and add a second copy of our Countries shapefile. Drag
it below your current layer in the Layers panel. Now, let’s rename it “No Data”
by right clicking on that layer and selecting “Rename Layer.” Let’s also set it to a
GEOG 360: GIS & Mapping
neutral color (ex. gray), but one that will stand out from the colors on your map.
You can change the color either by going to Properties → Symbology → Single
Symbol or you can simply double click on the color swatch next to your newly
renamed “No Data” layer.
c. Now, the 2019 emissions don’t tell the full story. One critique of comparing the
emissions of countries today is that some of the countries that have the most
green technologies have gotten to where they are because they emitted a lot of
carbon in the past. So, let’s change the map so that we are looking at cumulative
emissions.
d. Now, we can’t put two choropleth maps over one another, so let’s make a mixed
symbols map. Let’s make a dot density map of 2019 emissions to place over our
choropleth map of cumulative emissions. Go back to Lab 2 for a refresher on
how to make a dot density map. For this map, given the scale of our data, let’s
start with one dot to 10 million (10,000,000) metric tons of emissions (though
feel free to edit that if you decide you want to.
e. Now, remember that a dot density map is really about illustrating a density, so
we will want to choose an equal area map in order for that density to be
meaningful. Change the map view to an equal area projection of your choice.
MAP 1: For your first map, please make a mixed symbols map with a choropleth
layer illustrating cumulative CO2 emissions and a dot density map illustrating 2019
emissions. Be sure that you have selected an appropriate projection. In a textbox
on your map, tell us the map projection you have chosen, why you have chosen it,
and what the map tells us about the relationship between cumulative and current
CO2 emissions.
6. Now, let’s learn how to reproject your data into another CRS.
a. Remember that sometimes we want to actually change the CRS of our data, not
just of the map view. Typically, we will want to do this for analysis purposes (we
will see examples of this being important in future labs). While we don’t need to
do this now, let’s learn how.
b. To reproject a layer, click Vector in the menu bar at the very top of your window.
Select Data Management Tools and then Reproject Layer.
c. For demonstration purposes, we will be reprojecting our Countries shapefile, so
select Countries as the Input layer and then assign a CRS of your choice as the
Target CRS.
GEOG 360: GIS & Mapping
d. Once you select a CRS you’ll see a transformation (or maybe more than one)
appear in the Coordinate operation box. Stick with the default (this should be
the top one if there are more than one).
e. Under “Reprojected” use the “…” button and “Save to File” to save your new
reprojected layer into your class GIS folder and then click Run.
f. You’ll see your new shapefile, stored in a new CRS, appear on your map. Note
that it doesn’t appear in the projection that it is stored in, but rather in the
projection that the map view is in. In other words, it is being projected on the
fly.
7. We can also create our own CRS.
a. Let’s use our new reprojected layer to examine the concentrations of particulate
matter by country. Unlike greenhouse gasses which spread globally, particulate
matter only travels up to a couple hundred miles. As such, we might want to
represent it differently. For our purposes, we will be making a planar
orthographic projection that is centered on a location on the globe of your
choice and then we can see concentrations of particulate matter in the
surrounding area.
b. Let’s start by displaying the particulate matter data on our map using our
symbology tab. Feel free to classify that data as you like.
c. Now, let’s build our custom CRS. First, you’ll need to select a place in the world
that you want to be your focus and look up the latitude and longitude
coordinates of that place. We will be using decimal degrees and positive values
to represent degrees north or east and negative values to represent degrees
south or west. So, Seattle’s coordinates would look like:
Latitude: 47.612
Longitude: -122.336
d. Now, click Settings from the menu at the top of your window and select “Custom
Projections…”. In the pop-up window, click on the green plus button on the righthand side. Where it says “Name”, give your new CRS a name that you will
remember.
e. For Format, we are going to use “Proj String” so select that in the drop down
menu.
f. In the Parameters box, type the following line:
GEOG 360: GIS & Mapping
+proj=ortho +lat_0=AAA +lon_0=BBB +x_0=0 +y_0=0 +datum=WGS84 +units=m
+no_defs
Where it says AAA above, put the latitude of your chosen focal point. Where it
says BBB, put the longitude. So, if we were making a CRS for Seattle, it would
look like the line below:
+proj=ortho +lat_0=47.612 +lon_0=-122.336 +x_0=0 +y_0=0 +datum=WGS84
+units=m +no_defs
When you have that set, click OK.
g. Now, creating the new CRS won’t actually set that for your map view, so click on
the Current CRS button in the lower right-hand corner of your map. Type the
name you assigned to your projection into the Filter box and select that
projection. Click OK and examine your new projection.
MAP 2: For your second map, please make a choropleth map of particulate matter
concentrations using an orthographic projection you made centered on a place of
your choice. In a textbox on your map, tell us the location you chose to be the
center of your projection.
8. Finally, let’s learn how to add coordinates directly onto our map from a table.
a. We are going to be adding coordinates from the “Regions” table in the Lab 4
data folder. Go to Layer in the menu at the top of your screen and select Add
Layer → Add Delimited Text Layer. Use the “…” button at the end of the File
name row to select the Regions file.
b. Likely QGIS will do all of this by default, but double check that CSV is the selected
File Format and that the X field is listed as Longitude and that the Y field is listed
as Latitude. Click “Add” at the bottom of the window and then close the
window.
NOTE: Students often mix up latitude and longitude in terms of which should be
the x field/coordinate and which should be the y field/coordinate. Because
longitude tells us how far east or west (i.e. how far left or right) a point is, it is
your x coordinate. Because latitude tells us how far north or south (i.e. up or
down) a point is, it is your y coordinate.
c. You should see a series of points appear on your map representing six regions of
the world.
GEOG 360: GIS & Mapping
d. Use those points and what you learned about creating a proportional symbol
map in Lab 2 to create a proportional symbol layer of cumulative CO2 emissions
by region.
MAP 3: For your third map, please make a mixed symbol map with a proportional
symbol layer showing cumulative emissions by region and a second layer mapping
some other piece of data of your choice. This map should be in a different
projection than either of your first two maps. In a textbox on your map, please
explain the choices you made as a map maker and what the map tells us.
9. Submit the three maps you made above to the Lab 4 submission portal. Use the print
layout to make sure that each includes a legend, appropriate title, and the textbox
asked for in the prompts above.
Skill Development Lab 4 Rubric
Criteria
Map 1 (mixed
symbols map –
dot density +
choropleth)
Overall efficacy
of map/visual
hierarchy
Map 1
Projection
Ratings
15 pts.
Map employs
thoughtful visual
hierarchy to
make an
argument about
the distribution
of emissions.
That argument is
explained /
reinforced in the
textbox and
through an
informative title
and legend and
an effective
classification
scheme.
5 pts.
10 pts.
5 pts.
0 pts.
Map submitted,
shows clear
effort, but does
not show strong
attention to
visual hierarchy.
The argument is
not well or fully
explained /
reinforced in the
textbox or
supported by
the title, legend,
or classification
scheme.
Map submitted,
but does not
effectively
communicate a
message with
the map reader.
No map
submitted.
3.5 pts.
2 pts.
0 pts.
Map is projected Map is projected A map
in a projection
in a projection
projection is
appropriate to
appropriate to
explained, but it
Map projection
is not explained.
GEOG 360: GIS & Mapping
Skill Development Lab 4 Rubric
the map type,
and that
decision is wellarticulated.
10 pts.
the map type,
but that decision
is not wellarticulated.
7 pts.
is not a
projection
appropriate to
the map type.
4 pts.
Map employs
thoughtful visual
hierarchy to
make an
argument about
the distribution
of particulate
matter.
10 pts.
Map submitted,
shows clear
effort, but does
not show strong
attention to
visual hierarchy.
Map submitted,
but does not
effectively
communicate
with the map
reader.
No map
submitted.
7 pts.
4 pts.
0 pts.
Projection
Projection is an
orthographic
map projection
centered around
the point given
in the textbox.
There is limited
No map
evidence that an submitted.
orthographic
projection
centered around
a unique point
was attempted.
Map 3 (mixed
symbols map –
proportional
symbol + other)
10 pts.
An orthographic
projection
centered around
a unique point is
clearly
attempted, but
not successfully
executed.
7 pts.
4 pts.
0 pts.
Map employs
thoughtful visual
hierarchy to
make an
argument about
the distribution
of emissions.
That argument is
explained /
reinforced in the
textbox and
through an
informative title
and legend and
an effective
Map submitted,
shows clear
effort, but does
not show strong
attention to
visual hierarchy.
The argument is
not well or fully
explained /
reinforced in the
textbox or
supported by
the title, legend,
or classification
scheme.
Map submitted,
but does not
effectively
communicate a
message with
the map reader.
No map
submitted.
Map 2
(orthographic
map of
particulate
matter
concentrations)
Overall efficacy
of map/visual
hierarchy
Map 2
Overall efficacy
of map/visual
hierarchy
0 pts.
GEOG 360: GIS & Mapping
Skill Development Lab 4 Rubric
Map 3
Projection
Map 3
Explanation of
choices
classification
scheme.
5 pts.
3.5 pts.
2 pts.
0 pts.
Map is projected
in a projection
appropriate to
the map type,
and that
decision is wellarticulated.
5 pts.
Map is projected
in a projection
appropriate to
the map type,
but that decision
is not wellarticulated.
3.5 pts.
A map
projection is
explained, but it
is not a
projection
appropriate to
the map type.
2 pts.
Map projection
is not explained.
Textbox does a
great job of
explaining and
justifying the
choices made by
the map maker.
Textbox does a
good job of
explaining the
choices made by
the map maker.
Textbox
attempts to
explain the
choices made by
the map maker,
to limited effect.
To explanation
of choices
included.
0 pts.