Welcome back to the U.S. Census Open Mapping Series this is GIS module 2, Basics of QGIS.
In this module, we will learn the basic tools and menu options within the QGIS interface.
You will download and add US Census Tiger data to the map, explore these map data, and
save your map. With breaks for self-paced learning, it should take you about 15 to 20
minutes to complete, let's get started. Part 1, the QGIS Interface. In Module 1 you installed
QGIS. Look for the QGIS icon on your desktop in your downloads folder, or in the Start
menu. Double click on it to open, be sure to choose QGIS desktop 2.18 and not the QGIS
browser. We'll take a moment or two to load depending on your computer. A tip screen will
appear each time you start the program that provides helpful information as you learn
the program. Close the tip screen. Note it can be turned on and off under settings options
general. If you have any recent projects, they will show as shortcuts on the map canvas.
First let's go through the interface and toolbars, along with the top, you have the main menu
bar, this provides access to various QGIS features using a standard hierarchical menu.
Click on each menu item to explore the contents. Tools provide quick and easy access to map
interaction tools including many of the same functions as in the menu. Hover your cursor
over the tools to display a short description of the purpose. Hover over the vertical line
to find out what toolbar you are viewing. Toolbars can be reorganized, added, or switched
off. If they are not visible in a toolbar, all tools remain accessible via the menu.
If you hide a toolbar, you can restore it by choosing menu, view toolbars. Panels are
special widgets that you can interact with when performing advanced tasks. We will not
be using the browser panel in these modules; please close it using the X in the corner.
The layer panel provides a list of all the layers added to the map. The layers tools
allow you to add different types of geospatial data to the map. Layers are displayed in the
order which they are listed in the layers panel. Drag and drop to reorder, the map canvas
to the right will display these layers. The status bar along the bottom of the interface
notifies you of any updates, shows the current placement of your mouse, your current scale,
magnification level, rendering control, and the current coordinate reference system of
your map. Pause the video now and take a few minutes to explore the different components
of the QGIS interface. In part 2 you will start creating a map. For this map, we will
be using Tiger data from the US Census Bureau. Tiger has existed for 25 years, and tiger
shapefiles are designed to be used in a GIS. You'll need to download the data from the
US Census Bureau website. First, create a new folder on your desktop, call it census
data. Then open a browser and navigate to www.census.gov. Click on geography, click
on maps and data. Next, choose Tiger products, click on Tiger lines shapefiles. Scroll down
and click download, choose web interface. Use the drop-down arrows and select year 2017,
select a layer type, States and equivalent. Click Submit, click download, national file.
Now, save the file in the new folder, census data. Return to the webpage, click on return
to Tiger line shapefiles main. Repeat the steps to download a Roads shapefile. Select
Florida from the drop-down in primary and secondary roads. Click download, save to your
census data folder. Return to the web page, click on return to Tiger line shapefiles main.
Repeat the steps to download a Places shapefile, select Florida from the drop-down, click download.
Save the file to your census data folder, open the census data folder on your desktop.
Unzip the three files you just downloaded. Open QGIS by clicking on that QGIS desktop
2.18.17 icon. Read the tip and click ok. Start a new project by clicking on project new,
or by using the new tool. We're going to add some layers to start creating a map. To do
this, go to layer add layer add vector layer, or click on the add vector Data button. If
you are unsure of the button, hover over each button to see each function. Click browse,
navigate to your census data folder on the desktop. Double-click on the TL 2017 US State
folder. One file should be visible, if not, make sure that the file type is set to ESRI
shapefiles and then click open. You will return to the original add layer window, and the
source should now how the dataset name. Click open, your map you should now show a map of
the United States the layers panel should show TL 2017 US State Vector Layer in the
list. Now let's add some roads to the map. Click on the add vector Data button again,
and repeat the steps. This time, choose the TL 2017 roads file. Again, one file should
be visible, if not, make sure that the file type is set to ESRI shapefiles. Roads should
now be visible on top of the Florida portion of the map of the United States. The layers
panel will display both roads and the state layer. Now that you've added US States and
Florida roads let's add Florida places. Click on, the add vector Data button one more time.
Repeat the steps, this time choosing the TL 2017 12 place file. Now that you have some
data on your map canvas, it is a great time to save. To do so, click either project, save,
or click the save as button. Name your project Florida places, and save to your census folder.
Now you can investigate some of the map data. Zoom into the continental United States, choose
the zoom tool and select that area. With the state fire highlighted in the layer panel,
click the identify features tool. Click on Texas, the state will be outlined in red,
and an information box will open displaying the attributes of the chosen state or feature.
Take a minute to explore the US. Click in the white space around the US to unselect,
use the map navigation toolbar to navigate the map. You can also use the mouse wheel
to zoom in and out of the map and the arrow keys to pan. Let's zoom in to Florida now
and take a closer look at the data. There are 4 different ways to do this, use your
mouse wheel and scroll forward. Use the zoom tool, and also right-click on the roads layer
in the layers panel and choose the first option, zoom to layer because this is a Florida only
Road layer it will zoom to that extent. Now let's investigate the data we downloaded by
looking at the attribute tables. To do so, highlight a layer and right-click. Click on
open attribute table, or highlight the layer in the layer panel, and click the attribute
table tool. You'll notice that each state has a row in the attribute table. Click on
a row to highlight that state, unselect that state by using the unselect highlighted tool
button. Pause the video now, and take a few minutes to explore the attribute tables of
the three data layers. Congratulations, you have completed module 2. In the next module
you will learn how to style these layers and compose a printed map. Please keep QGIS open
if you are continuing to Module 3.