Just outside of our Esri office in Colorado USA, a large condominium complex just broke ground. To the spatial thinker, its construction invites consideration of scale, change, and geography. On a local scale, the hilltop site was chosen because of the excellent views its residents will have of the Colorado Front Range. This view, by the way, was formerly enjoyed by my colleagues on the north end of our building! On a regional scale, construction occurs here as part of population growth fueled by the combination of high-tech industries, including GIS software, data, and services, and amenities such as nearby universities and the Rocky Mountains, making the Front Range of Colorado one of the fastest growing regions of the USA for the past three decades.

For centuries, communities around the world changed very little, and indeed, some communities today undergo very little change. Yet in most communities, changes in infrastructure, total population, and the makeup of that population are commonplace. In the past, for the geography instructor, examining community changes spatially required a great deal of time to research, purchase, assemble, and reproduce the relevant maps and imagery. Today, community changes can be examined easily and freely by using a Geographic Information System (GIS).

One way to do this is to start examining regional scale changes by comparing historical to recent Landsat satellite imagery by using the Change Matters website. Using this site, you can examine changes from the UK Midlands to the Aral Sea using side-by-side views of images and the land use differences.



At a local scale, use ArcGIS Online, a webGIS from Esri. Start a new map and add three types of basemaps for any given area: Bing imagery, the ArcGIS Online imagery, and the topographic maps layer. Toggle the layers on and off and/or make them semi-transparent so that you can compare and contrast them. These three sources were created on different dates, and thus they provide an easy and powerful way to examine changes in local communities. Another way to analyze change is through demographic shifts. Open demographic maps, such as from the World Bank in ArcGIS Online, and study agriculture and rural development, gross national income, population change, and other variables. Collaborate with other educators and students or youth clubs across your city or across the country and compare your community’s characteristics with your collaborators. Why do differences exist? What will these communities look like in 10 years? In 25 years?



Where do you suppose these two pictured neighborhoods are?* What clues exist that help you determine their locations?

Take pictures and videos around your local community. Write text and make sketches about what you see. Revisit the same sites during different weather events and in different seasons, or in the case of my Esri neighborhood in Colorado, after the construction is completed. Link these photographs, videos, and text to points on your maps in ArcGIS Online. What changes are occurring, and why? What will your community look like and be like in 5 years? In 20 years? What can you do to influence your community in a positive way?

Joseph Kerski

*Answers: San Diego (left); Queens, New York (right)