Even though the dates and base Landsat images have not changed, the interpretations have been improved and refined. Because of this, EVERY MAP has changed. For example, 1985 Version 1 land cover is different from the 1985 Version 2 land cover.
Version 1
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Version 2
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Agricultural Field. This is the only new class added to the Version 2 land cover. The Agricultural Field class came almost entirely from the Other Grass class of Version 1 land cover. 70% of Version 1 Other Grasses became Agricultural Field in Version 2. For more about how Agricultural Field was determined, visit its FAQ.
2002 Version 1 |
2002 Version 2 |
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Developed. There is slightly less developed area in Version 2 compared to Version 1 maps of the same date. This is not because the actual developed area changed! It is because the maps are doing a better job of identifying forest canopy in urban areas. Below, red is Developed and green is Forest.
2002 Version 1 |
Difference |
2002 Version 2 |
Green on the difference image shows areas that were developed on the 2002 Version 1 but Forest on the 2002 Version 2. This represents a refinement of tree canopy in urban areas. |
Turf and Grass. There are two parts to the Turf and Grass story. The first part of the story is the areas changed FROM Turf and Grass in Version 1 TO Other Grass in Version 2. These areas were generally around airports.
2002 Version 1 |
Difference |
2002 Version 2 |
Yellow on the difference image shows grassy areas around an airport that were Turf and Grass in Version 1 and are Other Grass in Version 2. |
The second part of the Turf and Grass story is that there is a 40% increase in Turf and Grass in Version 1 as compared to Version 2. This refinement occurred mostly in residential areas where roads and buildings were surrounded by Other Grass in Version 1 and are more accurately surrounded by Turf and Grass in Version 2.
2002 Version 1 |
Difference |
2002 Version 2 |
The yellow on the difference image shows areas that were Other Grass in Version 1 and are Turf and Grass in Version 2. This represents a refinement where grassy areas in a neighborhood are correctly classified as Turf and Grass. |
Other Grasses. The Other Grass class has received significant refinement.