Getting Started with QGIS: Your First Map

Overview

Questions

• How do I load spatial data into QGIS, including directly from the web?
• How do I explore a layer’s attributes?
• How can I style point data by category and polygon data by value?
• How do I create and export a finished map layout?

Objectives

• Add a basemap and load a vector layer from a web address
• Explore a layer’s attribute table
• Style points with categorized symbology
• Build a choropleth map with graduated symbology and compare classification methods
• Create a print layout with title, legend, scale bar, north arrow and source, and export it

Before you start

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You need QGIS installed. If you have not installed it yet, or the interface is new to you, follow the Setup page first. These steps were written for the QGIS 3.x Long Term Release; menus may differ slightly in other versions.

We will use two small datasets hosted with this lesson. You do not need to download anything: QGIS can read a file directly from its web address.

Dataset	Web address	Contents
Alaska airports (points)	https://raw.githubusercontent.com/SpatialTurn/Foundations/main/data/alaska_airports.geojson	76 airports with name, use (civilian, military and so on) and elevation. From the QGIS sample dataset.
Indiana counties (polygons)	https://raw.githubusercontent.com/SpatialTurn/Foundations/main/data/indiana_counties.geojson	92 counties with pop_2012, land_sq_mi, density (people per square mile) and unemp_2016 (percent)

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Part 1: Add a basemap

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A basemap gives your data geographic context.

1. In the Browser panel (usually on the left), expand XYZ Tiles.
2. Right-click OpenStreetMap and choose Add Layer to Project.
3. A world map appears in the map canvas.

If you do not see the Browser panel, open it with View > Panels > Browser.

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Part 2: Load a layer from the web

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1. Go to Layer > Add Layer > Add Vector Layer.
2. Under Source Type, choose Protocol: HTTP(S), cloud, etc.
3. Leave Type as HTTP/HTTPS/FTP.
4. In URI, paste the airports web address from the table above.
5. Click Add, then Close.

The 76 airports appear as points over Alaska, and a layer called alaska_airports appears in the Layers panel.

6. If the points are hidden under the basemap, drag alaska_airports above OpenStreetMap in the Layers panel. Layers at the top of the list are drawn on top.
7. Right-click the airports layer and choose Zoom to Layer.

Callout

Loading local files

To load a file saved on your computer instead, keep Source Type as File and browse to it. For a shapefile, select the .shp file; the .dbf, .shx, .prj and .cpg files with the same name must be in the same folder.

Save your project now (Project > Save, which creates a .qgz file) and save regularly as you work.

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Part 3: Explore the attributes

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1. Right-click the airports layer and choose Open Attribute Table.
2. You should see 76 rows, one per airport, with the columns name, use and elevation.
3. Click the use column header to sort it. How many airports are military?

The attribute table holds the data behind the map. Every styling choice you make next is based on one of these columns.

You can also click a single airport with the Identify Features tool (the “i” icon on the toolbar) to see its attributes.

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Part 4: Style the points

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First, give the airports a clearer symbol than the default dot.

1. Right-click the airports layer and choose Properties, then the Symbology tab.
2. With Single Symbol selected at the top, scroll the symbol library at the bottom and choose a marker such as topo airport. Set the Size to about 5 millimeters.
3. Click Apply.

Layer Properties, Symbology tab, with the topo airport marker selected

Now color the airports by how they are used:

4. Change Single Symbol to Categorized.
5. Set Value to use.
6. Click Classify. Each airport type gets its own color.
7. Double-click a symbol to change its color or size. Use clearly different colors (or shapes) for the four types.
8. Click OK.

Each renderer is suited to a type of data:

Renderer	Use for	Example
Single Symbol	Showing where things are	All airports in one style
Categorized	Categories (no order)	Airport use
Graduated	Numbers (low to high)	County density

To rename the layer, as it will appear in the legend, open Properties > Source and change the Layer name (for example, to “Airports by use”).

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Part 5: Build a choropleth map

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Now load the Indiana counties and shade them by population density.

1. Load the Indiana counties web address the same way as in Part 2.
2. Open Properties > Symbology and change Single Symbol to Graduated.
3. Set Value to density.
4. Choose a Color ramp such as Blues or Viridis.
5. Set Mode to Natural Breaks (Jenks) and Classes to 5.
6. Click Classify, then Apply (not OK yet).
7. Change Mode to Equal Interval, click Classify and Apply. Then try Equal Count (Quantile). Watch how the map changes.

Population density in Indiana is very skewed: most counties have fewer than 200 people per square mile, and Marion County (Indianapolis) has over 2,000. With Equal Interval, almost every county lands in the lightest class. Choose the mode that best shows your message, and click OK.

Callout

Why density and not population?

The layer also has pop_2012, a count. Shading areas by a count mostly shows where big counties or big cities are. Density (people per square mile) is a rate, so it can be compared fairly between counties of different sizes. See the Normalization section of the Data Visualization module’s Fundamentals of Map Design episode.

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Part 6: Create a map layout

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To export a finished map with all its elements, use a Print Layout.

1. Go to Project > New Print Layout and give it a name.
2. Add the map: choose Add Item > Add Map, then click and drag a rectangle on the page.
3. Add a title: choose Add Item > Add Label, drag a box above the map, and type your title in the Item Properties panel. Make it large.
4. Add a legend: choose Add Item > Add Legend and drag a box. In Item Properties, you can rename entries and remove the basemap from the legend.
5. Add a scale bar: choose Add Item > Add Scale Bar. Set the units to miles or kilometers.
6. Add a north arrow: choose Add Item > Add North Arrow.
7. Add a source line: add another label at the bottom with the data source and your name, for example “Data: U.S. Census Bureau, BLS. Map by A. Student, 2026.”

Print Layout with the Add Item menu open

Use Item Properties to change fonts, sizes and frames. Use the Move Item Content tool to pan the map inside its frame without moving the frame.

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Part 7: Export

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1. In the layout window, choose Layout > Export as Image (PNG) or Layout > Export as PDF.
2. Choose a file name and location and accept the default options.
3. Save the project again (.qgz). The layout is saved inside the project.

An example finished layout: airports in Alaska

This example uses a single airport symbol. Your version will also show the airport types from Part 4. Notice that it is missing one element from our list: a data source line.

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Common beginner mistakes

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• Forgetting to save the project
• Mapping counts instead of rates on a choropleth map
• Leaving layer names such as indiana_counties in the legend
• Using too many classes or a rainbow color ramp
• Leaving out the source line, legend or title

Callout

Keep it simple

Start with a clear, simple map. Add complexity only when it helps the reader.

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Hands-on exercise

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Challenge

Challenge 1: An unemployment map of Indiana

Using the Indiana counties layer, create and export a finished map of 2016 unemployment rates (unemp_2016).

1. Use Graduated symbology with 5 classes and a sequential color ramp.
2. Try two classification modes and pick the one that shows the pattern best.
3. Build a layout with a title that states what the map shows, a legend with units (%), a scale bar, a north arrow and a source line.
4. Export it as a PNG.

Show me the solution

• Value: unemp_2016. Color ramp: a single hue such as Oranges or Blues (light for low, dark for high).
• Mode: unemployment ranges only from about 3.1% to 6.6% and is not very skewed, so Natural Breaks or Equal Interval both give readable maps. Quantile also works if the message is about rankings.
• Legend: rename the layer to something like “Unemployment rate, 2016 (%)”.
• Title: for example, “Unemployment was highest in northwestern and southern Indiana in 2016”. Check your own map before writing a conclusion like this.
• Source: “Data: U.S. Bureau of Labor Statistics, 2016.”

Challenge

Challenge 2: Fix the projection (optional)

Alaska looks stretched over the OpenStreetMap basemap, which uses Web Mercator. Change the project’s coordinate reference system to one designed for Alaska and compare.

Show me the solution

Click the EPSG code in the bottom-right corner of the QGIS window (or Project > Properties > CRS), search for 3338 (NAD83 / Alaska Albers), select it and click OK. The map is redrawn in an equal area projection for Alaska, and the state no longer looks enormously stretched. The basemap is reprojected too, although its labels may look slightly blurred.

Callout

Layer CRS and project CRS

Every layer has its own coordinate reference system (CRS), shown under Layer Properties > Information. The project also has a CRS, shown in the bottom-right corner of the window. QGIS reprojects layers on the fly so that they line up on screen, which is convenient but can hide a layer with a wrong or missing CRS. Two habits avoid most problems:

• Before measuring distances or areas, set the project CRS (and reproject layers you will analyze) to a projected system in meters, such as EPSG:26916 (UTM zone 16N) for Indiana.
• If a layer appears in the wrong place, check its CRS before anything else.

Notebook 4b in this module shows the same ideas in Python, and the Data Management module’s Coordinate Reference Systems episode explains the theory.

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Final takeaways

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• QGIS is a free, powerful tool for designing maps.
• Layers can be loaded from files on your computer or directly from a web address.
• Categorized symbology suits categories; graduated symbology suits numbers.
• The print layout is where map elements (title, legend, scale bar, north arrow, source) come together.

Discussion

• What challenges did you face while making your first map?
• How would you change your map for a different audience?

Key Points

• Add Vector Layer with the HTTP(S) protocol loads data straight from a web address.
• The attribute table holds the data behind every styling choice.
• Use Categorized for categories and Graduated for numbers, and compare classification modes.
• A Print Layout combines the map with its title, legend, scale bar, north arrow and source.
• Save the project often; export layouts as PNG or PDF.
• Check layer and project coordinate systems before measuring anything.