App of the Month: Our Changing Continent
April is Earth Month – a perfect time to share this month’s App of the Month. The Our Changing Continent story map uncovers the stories that are hiding in an incredible North American Land Change dataset and highlights continent-wide issues that transcend borders.
Introduction
One of the great things about working in GIS is coming across datasets that change your perspective on the world. However, sometimes datasets do not immediately reveal the many stories that are hidden within them. The Our Changing Continent story map by the Commission for Environmental Cooperation (CEC), aims to shed light on the expansive 2010-2015 Land Cover Change in North America dataset. Using ArcGIS StoryMaps as a medium, the CEC has created an application which breaks down borders and draws attention to the interconnectedness of our continent.
Data
The 2010-2015 Land Cover Change in North America (30m) dataset was created by the CEC through their North American Land Change Monitoring System (NALCMS). It is the result of an impressive collaboration between numerous government agencies spanning the continent and is a key component of the North American Environmental Atlas. The dataset was created by examining land cover change between 2010 and 2015 using data from Landsat satellite imagery. The Our Changing Continent story map includes a link to the data for you to download and explore.
Application
To share the spatial and statistical information contained within the dataset, the CEC chose to develop an ArcGIS StoryMaps application (check out what's new in StoryMaps). For the CEC, StoryMaps allowed them to combine different types of media and geospatial information into a coherent application. In addition, users of all GIS abilities could contribute to the app due to its ease of configuration.
Part of the power of ArcGIS StoryMaps is the ability to embed other maps and applications. This is readily seen in the embedded Swipe Map story map, where users can swipe maps to see land cover changes over the past 5 years. The growing aquaculture industry in Sinaloa, Mexico is a great example of how demand for resources in one part of the continent effects the land in another. In this case, the demand for shrimp in the U.S. has altered coastal ecosystems in the Gulf of California:
(the above image is a GIF)
There are many other stories that are highlighted in the Swipe Map and I would highly recommend heading over to the app to learn more.
Challenges
One of the biggest challenges the CEC faced was how to incorporate these large datasets into the application without impacting the user experience. As a tech support analyst, I am often asked how to improve the performance of large datasets in ArcGIS Online. Our recommended approach is to create tile packages in ArcGIS Pro ahead of time and upload them to ArcGIS Online. Check out the Publish large tile packages section in our documentation if you are curious about this workflow.
The result of the CEC’s initial processing is an application that runs smoothly even with datasets that are well over a gigabyte in size.
There are many other components of this app that are worth exploring. (Make sure to check out the Broad Land Change Gains and Losses section.) Using ArcGIS StoryMaps, the CEC has successfully developed a powerful tool for bringing spatial information and statistics to the public. They have done an excellent job of analyzing and presenting large-scale changes to the continent that will open your eyes to the pace of change impacting our environment.
This post was translated to French and can be viewed here.