Why are there discrepancies between my previous Legacy NLCD data results and the newer Annual NLCD data for the same years, and can I still compare them?

These differences can lead to discrepancies in land cover classification, where the “differences” may reflect methodological changes rather than actual land cover change. For accurate analysis, you should only compare data from the same release (e.g., comparing 2001 data from the 2021 release with the 2021 data from the same 2021 release). Legacy data spans from 2001 to 2021 and is consistent within each release, but comparing across different releases or with Annual NLCD data will yield inaccurate results. To conduct a proper analysis, it is best to download the currently released data for the specific years you are interested in.