Compare the sizes of countries with this new 3D web mapping application

05-16-2022 10:59 AM
Esri Notable Contributor
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A concept that is central to the teaching of GIS, geography, environmental science, and other disciplines is scale.  One effective way to teach about scale is to use a subject that most people have at least some grasp of--world countries.  This amazing new 3D web mapping application allows instructors and students to quickly and effectively compare the sizes of world countries.  It thus can serve as an effective way to teach and learn about scale and related concepts.   See my video for additional exploration and information. 

To use the application, all you need is a web browser and internet connection. No sign-in is required.  Click on a country, and then use the controller bars that appear to move that country to another location on the Earth.  In the example below, I am overlaying India on top of the continental USA, and I see that India's size makes it "extend" partway into Canada and Mexico.  I challenge you to use this tool also to foster knowledge about the shape and size of countries that your students may be completely unfamiliar with. 


I encourage you also to use this application to tilt the Earth so that north is not at the top, to provide an extra challenge.  Compare this 3D application to 2D maps in ArcGIS Online and discuss the differences with your students.  

This application provides an easy way to teach about the age-old issue with size and shape distortions for land masses using the Web Mercator projection.   So, go ahead and use the application to place Greenland atop Brazil:  Unlike the perception resulting from maps in unprojected spaces or in Web Mercator, in reality, Brazil really is much larger than Greenland!


I have long been an advocate for teaching about scale.  Scale is important to studying changes over space and over time. Scale is fundamental to teaching about the interaction between the biosphere, anthroposphere, lithosphere, cryosphere, atmosphere, and hydrosphere.  The scale of your study and the scale and resoluton of the data you are using impacts all the analysis you do in a GIS.  To teach about these concepts, you could use these 15 videos in my "scale matters" playlist.  Or, you could use the USGS basemaps in ArcGIS Online, examining the difference between the 1:250,000-scale, the 1:100,000-scale, and the 1:24,000-scale maps that are in that set of basemaps.  What features are shown at each scale, and how are they rendered in terms of their symbology?  Or, you could compare 15m Landsat imagery with 1m satellite imagery with 15cm UAV Drone imagery.  Or, you could compare selected demographic variables by county vs zip code vs census tract vs block groups, discussing the areal extent of each polygon and the patterns that may be evident at certain scales but not at others.  The 3D web mapping application described in this essay provides one more way to teach about this important concept.    

You can also do something similar on Mars, using the tool and the questions I pose here.  Place France on Olympus Mars, or place Texas on the crater where the Perseverance landed in 2021.  You can also place buildings and landforms on physical features on Mars, such as the Grand Canyon on top of the Valles Marineris.  Not only are these Earth and Mars web mapping applications important teaching tools, but they are also fascinating and fun. In fact, if your students don't say "cool!" while using these tools, I would be very surprised.

This application was developed by my colleague Arno Fiva, to whom I am grateful.  Arno is focused on creating 3D web apps using the ArcGIS API for JavaScript.  Arno has a very interesting job--encourage your students to learn JavaScript and Python and other GIS-related development tools as well, so that they can be inspired to pursue similar career paths!  Follow Arno's work on Twitter, here.

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About the Author
I believe that spatial thinking can transform education and society through the application of Geographic Information Systems for instruction, research, administration, and policy. I hold 3 degrees in Geography, have served at NOAA, the US Census Bureau, and USGS as a cartographer and geographer, and teach a variety of F2F (Face to Face) (including T3G) and online courses. I have authored a variety of books and textbooks about the environment, STEM, GIS, and education. These include "Interpreting Our World", "Essentials of the Environment", "Tribal GIS", "The GIS Guide to Public Domain Data", "International Perspectives on Teaching and Learning with GIS In Secondary Education", "Spatial Mathematics" and others. I write for 2 blogs, 2 monthly podcasts, and a variety of journals, and have created over 5,000 videos on the Our Earth YouTube channel. Yet, as time passes, the more I realize my own limitations and that this is a lifelong learning endeavor and thus I actively seek mentors and collaborators.