Here’s how to make a side-by-side layout in ArcGIS Pro comparing the same place at two different points in time, using the World Imagery Wayback imagery archive. But be warned…you yourself will be a different person at the end of these eleven minutes…and how do we compare ourselves to past selves? What is it to know one’s self? What is time? Is it unidirectional? Are we progressing to a more orderly state or are we tumbling through the slow fingers of entropy into a colder and darker universe?
This video will answer literally all of these questions.
0:00 Absurd historical comparison illustration.
0:15 The World Imagery Wayback app. It lets you explore/steal any previous version of the Imagery basemap.
0:37 Check out the Beijing Daxing International Airport now, vs 2017. Incredible.
1:00 Using map notes to draw a polygon area of interest.
2:14 Reversing our area of interest with a Global Background rectangle and the Erase tool.
(A friendly YouTube viewer suggested a clever alternative, which is to create a massive buffer around my area of interest and exclude the input shape. Same result. Thanks GIS community!)
3:24 Mis-using the gradient stroke to approximate a dropshadow.
4:50 Creating a new layout, and inserting our map.
5:37 Creating a duplicate of the map in the Pro project. This will contain the historic imagery.
(Aubri Kinghorn just told me about a way better way to keep multiple map frames in synch with each other: Map Frame Constraints. Learn all about it here and see it retroactively worked into this map, here)
6:03 Back in Wayback, we can grab a link to a historic version of the Imagery basemap.
6:30 In Pro, we can add that historic imagery to our new, duplicate, map using Add Data – Data from Path.
7:00 In the layout, we scale down the map frame to half the area, duplicate it, and point to the new map frame.
7:57 Reconciling the geographic scales between the two map frames (copy/paste).
8:25 Removing the default black borders around the map frames.
9:30 Time to insert a title and whatever sort of annotation we want.
And that is it, friends! Can you make a layout comparing different thematic layers rather than different imagery vintages? For sure. Should you? Absolutely. Can you use this technique to create any manner of comparison maps? I think you know the answer is yes.
Happy Comparative Mapping! John
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