The power of maps
Maps provide windows to information
You can use maps to explore and discover the world.
- Open the Treasure Hunt: World Heritage Sites website.
- Click Get started.
In the side pane, there is an image of a UNESCO World Heritage site. A clue is shown below the image.
UNESCO stands for United Nations Educational, Scientific and Cultural Organization. It is a United Nations agency seeking to promote peace and security through education, arts, sciences, and culture.
- On the map, scroll your mouse wheel to zoom and click and drag to pan the map and locate the site.
Zooming means changing the scale of a map to see more or less detail. Panning means changing the extent to see different areas on the map.
When you get close enough, a pin and label appear.
Angkor Wat is a temple complex in Cambodia, built in the twelfth century.
- Don't click the Next Question button yet. Zoom in further to explore the site up close.
At a certain zoom extent, the basemap shows more details of the area. You can see the grounds of Angkor Wat and the wide rectangular moat that surrounds the temple.
- In the side pane, click the Next Question button. Locate the other heritage sites in this game and explore them up close.
To continue your exploration, try out more geography Treasure Hunt maps.
Maps do more than show where things are. They spark curiosity and prompt further questions, such as, What is nearby? Are there any patterns? Why does it look like that, and has it always been that way?
Maps are data
Maps not only provide a picture of what is on the ground, but they can help you visualize large sets of data and reveal trends.
Has anyone ever told you that all of the maps have already been made? What about a map of the earthquake that happened earlier this morning? Our world is constantly changing, and we will never run out of things to map.
- Close the Treasure Hunt map and open the U.S. Vessel Traffic map.
This map shows U.S. maritime activity and includes tools that allow you to explore the paths of vessels, visualize patterns, and download data. You can explore the paths of vessels and identify trends by time, vessel type, and place on data between January 2017 and June 2020.
You can learn more by exploring the Vessel Traffic ArcGIS Online collection.
Vessel traffic data is an important resource made available by the U.S. Coast Guard, NOAA (National Oceanic and Atmospheric Administration), and BOEM (Bureau of Ocean Energy Management) through Marine Cadastre. Vessel traffic data can help avoid ocean-based slow downs and crashes.
You'll start by exploring cargo traffic management.
- Zoom in to the coast of New York.
It is important for cargo ships to follow sea traffic rules and control their speed and course as they come in and out of major ports. On the map, you can see what looks like lanes on the open seas. Port managers define the lanes to keep the vessels safe.
Next, you'll see another example of how rules impact open seas traffic.
- In the list of vessel types, click Passenger.
The map is lit up with pink lines, indicating passenger ship traffic.
- Zoom in to Long Bay off the coast of South Carolina.
- Click the down arrow to change the year to 2019 and click Nautical Boundaries.
By turning on Nautical Boundaries, a line appears showing where the bounds of a country reaches beyond the land and into the ocean.
There are a number of line clusters out in the open water. Why might a passenger vessel sail just beyond the nautical boundary and return?
- Click one of the clusters located just beyond the nautical boundary.
A bar appears at the top of the application with the vessel name. This is a gambling vessel. In states where gambling is not legal, there are vessels that ferry passengers outside the nautical boundaries where the rules no longer apply.
Next, you'll explore an example during the first month of the COVID-19 response.
- On the map, navigate to the waters off the coast of San Francisco, California. Set the date to March (03) 2020.
There are a number of routes forming rectangular off the coast of San Francisco. What do you think was happening?
- Click one of the routes traveling in loops.
These were cruise ship vessels.
When medical personnel in the United States were first responding to the spread of COVID-19 in March 2020, cruise ships, which may have had COVID-19 cases on board, were not allowed to dock. These vessels, and their passengers, traveled in loops outside their ports for several days and weeks, waiting for clearance to dock.
Finally, you'll explore how patterns in vessel traffic reflect the cycles of nature.
- Zoom to the Cascadia Basin off the coast of the state of Washington, known for salmon fishing.
- Click Fishing and set the date to January (01) 2019.
- Increase the date by one month at a time and observe the changes in the vessel pattern.
When are the busiest fishing months of the year? You can see the fishing vessels appear according to the seasonal migration patterns of salmon at their peak in the months of May to October.
Maps can provide a context for understanding large amounts of data and for spotting patterns within it. This map contains so much data that it can't all be shown at the same time. By using the built-in tools for filtering the data, it enables you to ask questions and find answers using the map.
To learn more about the U.S. Vessel Traffic application, see Introducing the U.S. Vessel Traffic application from Living Atlas and Cool examples from the U.S. Vessel Traffic application from Living Atlas.
Maps tell stories
Maps don't only provide you with information. They can engage readers and tell immersive and compelling stories. Some maps guide your explanation to tell powerful and engaging stories. When maps tell stories, they turn information into knowledge and understanding.
Next, you'll explore a story that combines maps, text, and other graphics to bring geographic information to life.
- Close the U.S. Vessel Traffic application and open the Urban Africa story. Start scrolling and reading the story.
As you explore, be curious and click buttons and interact with the maps to get the full experience of an ArcGIS StoryMaps story.
- In the side panel, scroll down to the Population by the numbers heading.
A map of the African continent is displayed. The percentage of people living in cities is growing fast in countries like Egypt and Nigeria.
- Scroll down to the Urban centers, mapped section. In the side panel, click the Zoom in to North Africa map action button (you may need to scroll down).
The map zooms in to the North Africa region.
Map action buttons add an interactive component to maps in a story, allowing the reader to adjust the map view by turning the map action buttons on and off.
Among these urban centers are some of the oldest human settlements on the continent. Cairo is Africa's largest city with a population of nearly 23 million.
- In the side panel, scroll down to the section titled Agglomerations and rates of change, revisited.
Rapid population growth and development in rural areas have also led to the emergence of thousands of small urban agglomerations, or urban centers.
- On the map, click any of the red circles.
A pop-up appears with more information.
These map symbols represent the percentage of growth in the population from 2000 to 2015. Clicking each circle reveals a pop-up with information about the small urban agglomeration, the estimated population, and the percentage of growth.
- Scroll to the Dig into the data on your own section.
You can download the maps and data in this story. Including a way for viewers to access the data used in maps throughout the story provides opportunity for further learning and creativity.
- Scroll down to the end of the story to the section Recommended reads.
The story concludes with recommended links related to population growth.
Data is often complex, and benefits from being presented in clear and simplified manner. Maps offer intuitive visualizations that can communicate data as stories. Maps are often more effective than words and pictures alone. When maps tell stories, they become powerful tools to both educate and persuade.
Maps can communicate emotion
Maps don't only communicate information and knowledge. They can also make you feel and connect to emotions.
- Close the Urban Africa story and open the In America: Remember website and scroll down to the embedded web app with a map of flags.
The In America: Remember exhibit was a memorial and art installation on the National Mall in Washington, D.C., in September and October of 2021. The lawn on the National Mall was blanketed with more than 660,000 white flags, each representing a life lost to COVID-19. Visitors were invited to personalize and dedicate a flag for someone they lost, and using GIS technology, visitors who could not be there in person were able to dedicate a flag digitally.
The website includes a map that serves as a memorial to those who have died in the pandemic. Each flag on this map represents a life lost to COVID-19 and many of the flags include personal dedications and messages added by someone who wished to honor a loved one they lost.
- In the map, zoom in and click a flag.
The Info pane appears; it includes information about the flag you clicked. An image of the flag when it was on the lawn on the National Mall appears with a personal message, hand written from a loved one.
For those who submitted a flag online, a dedicated group of volunteers transcribed the messages onto a flag and took a picture to show the message was part of the exhibit.
The flags were organized by numbered sections so that a reference could be provided to locate a specific flag.
- Zoom in to section 106, click the flags, and read the messages that appear.
This section was dedicated to physicians and frontline health workers who lost their lives serving and providing medical care to others who had COVID-19.
- In the side pane of the app, click the information button to see the Details pane. At the bottom of the pane, click the COVID Lost Loved Ones map link.
This map features photos and messages of remembrance for the lives lost to COVID-19. While this map can't bring these people back, it can offer a space for mourning and remembrance. It allows us understand the losses from COVID-19 not as numbers, but as individual lives.
This map is an example of crowdsourcing, in which you invite anyone to contribute data and information to a survey or map. This is one of many ways you can collect data to show on a map.
Maps aren't just things that we read and consume. They are things that we contribute to and create. Maps offer us a way to engage with our communities, be they local, national, or global. We can use maps to share our own stories and to connect with one another.
To read more about the In America: Remember art installation, see A Place for National Mourning.
Maps provide innovative solutions
Maps don't only help identify and communicate challenges in our world—they also help inform decision making and identify solutions to address them. We can use maps to perform analysis and help improve our communities, prepare for emergencies, and plan for the future.
- Close the In America: Remember site and open the The air we breathe story.
This story explains the causes of poor air quality, shares data on air quality in maps, and illustrates the human impact of poor air quality.
Many maps start with questions that need to be answered or problems that need to be solved.
- Scroll down to the How is the air quality near me? section.
There are many ways to visualize air quality. One way is to view Air Quality Index (AQI) values.
- Explore the second map showing AQI values and determine what the current air quality data reading is in your area.
- Scroll to the PM 2.5 near me section.
Particulate matter, or PM, at the size of 2.5 micrograms per cubic meter is especially concerning to human health, as it is small enough to enter deep into lungs and even the bloodstream.
- Scroll further and explore the map in the PM 2.5 near me section.
- Scroll down to the The human impact section.
Poor ambient or outdoor air pollution is a major environmental health risk all over the world, increasing the chance of people developing diseases such as stroke, heart disease, lung cancer, and asthma.
- Continue scrolling through the Has air pollution decreased? section. Read and explore the maps until you get to the question: Are some people more impacted than others?
This map explores the relationship between areas with high PM 2.5 values and communities of color in the United States.
- Click the zoom out button and pan the map to see the entire country.
Maps can help visualize where new policies can address and improve equity.
This story is part of a collection of stories exploring air quality conditions and policies around the world.
- At the top of the story, click the next arrow to view the next story in the collection.
The title of the next story is Call to Action: End environmental racism now.
The beginning sections explain how the burden of environmental pollution is not evenly distributed throughout the United States and that communities of color, indigenous communities, and low-income communities are more likely to live and work in areas that have historically been disproportionately burdened with poor air and environmental pollution impacts. In particular, the African American population has been found to be 54 percent more likely to live in an area of heavy air pollution and under-resourced communities are 35 percent more likely.
By combining maps that show where there are high levels of PM 2.5 (in pink) and a high percentage of Black population (in blue), the relationship between the two is more evident.
- Scroll to the Newark, New Jersey section and explore the case studies presented.
Another way to visualize relationship in a map is to style layers using a relationship map. A relationship map displays two data values with a grid of colors, showing whether the two attributes have data values that are both high, both low, or individually high or low, with two different colors for each corner of the grid.
In this example, the darkest blue color represents areas where there is both a high PM 2.5 level and high Black population. The lighter blue areas represent where there is low PM 2.5 but a high percentage of the Black population, and the pink areas represent the reverse—areas with low Black population but high PM 2.5.
Learn more about relationship maps.
- Explore the We’re working on solutions section.
Government agencies, advocacy groups, and concerned residents can all use maps to make informed decisions about air quality policy. If racial equity and social justice are important components of the policy-making process, maps can serve as a useful tool for determining where to allocate resources where they are most needed.
You can continue exploring the remaining stories in the collection, which includes more maps, data, and tools for policy mapping in the United States and around the world.
View more maps, data, and tools for policy mapping in the United States at the Esri Maps for Public Policy site. For more resources on applying racial equity workflows to GIS, see the Racial Equity GIS Hub.
Every day, maps are created to help make decisions about everything from where to construct levies to how to limit the environmental impacts of new construction projects. Maps are powerful tools that you can use to analyze our world and make the important decisions that will shape it.
In this lesson, you learned about maps, but more importantly, you learned through those maps—about world heritage sites, vessel traffic, urbanization, remembering lost loved ones, and air quality policy. Maps offer you an interactive and compelling way to explore and learn more about the world. They can be intuitive tools for visualizing and manipulating data. They can turn that data into stories to educate, persuade, and remember. They can move people and influence important decisions.
You can find more lessons in the Learn ArcGIS Lesson Gallery.