Northern Colorado Land Use Changes

2017 to 2021

The map below allows you to toggle between 2017 and 2021 and view the differences in land use in that 4 year period. All land use data comes from the 10m Annual Land Use Survey which is created by feeding ESA Sentinal-2 imagery into a Deep Neural Network run on Microsoft's Planetary Computer. Each 10x10m square of the grid is classified into a 9-category system and these are displayed color-coded on the map.

As you scroll the map, the Sankey chart below it will update to reflect how the different land categories have changed.

Known issues

The selected dataset only includes the MGRS 13T zone - as you scroll south it'll stop finding map tiles. I think I could override the getTileURL function to support this, but it's beyond the scope of this project.
The Sankey calculation is done clientside on the fetched land use tiles, this makes it easy to implenent as live, but it can be a little slow on some computers and also means that it doesn't have access to more granular zoom levels and small changes could be missed
Computation of acreage changes is done by calculating the total area of the Map Boundary and then assuming each of the pixels is equal area. The nature of the EPSG:3857 Web Mercator projection means that this assumption becomes increasingly inaccurate as more degrees of latitude are included. For the scales shown here, this is usable, but a better calculation would be necessary to calculate ice-loss in Greenland.