The Annual National Land Cover Database (NLCD) was released in late 2024 as a reinvention of the prior NLCD, a longstanding and definitive national U.S. land cover resource valued by private industry, government agencies and university researchers.
New AI innovations made the Annual NLCD improvements possible, including providing a look at yearly land changes dating back to 1985. The previous NLCD was only able to offer new land cover data every two to three years and dated back only to 2001.
The primary source for Annual NLCD’s 16 land cover labels—for fields, forests, city development and more—is Landsat satellite imagery. Every satellite pixel, or 30-meter-by-30-meter plot, needed to be processed from 1985 to 2023 across the lower 48 states, which added up to 295 trillion pixels. With a goal of completing the entire release in two years, the development of more advanced methods was essential.
AI was used for both the classification, or labeling, of land cover types and also the detection of changes in land cover from year to year. That involved a lot of training data—helping the algorithms learn from labeled satellite data and from mistakes to predict labels and changes.
Rylie Fleckenstein, the Research and Development technical lead for Annual NLCD, discussed the deeper levels of machine learning used for Annual NLCD in the podcast episodes. Annual NLCD aimed for a faster, more automated approach that would not compromise on quality or consistency, versus slower methods in the past that relied more on human interpretation of imagery.
Deep learning is a type of machine learning that performs complex tasks and learns from the results, essentially training itself. Flecksenstein compared it to LEGOS. Rather than using the instructions to build a certain object in a certain way, he said deep learning is like “a box of LEGOS that you can construct in any way that you can think of that actually can better fit to your problem.”
Terry Sohl, Chief of the Integrated Science and Applications Branch at EROS, summarized how AI benefited not only Annual NLCD production and data users but also taxpayers. “A completely new methodology was stood up, all AI-based, linking three different AI models,” Sohl said. “We’re faster, we’re more efficient. We’ve saved the government and the taxpayers money, and we’re creating a superior product. It’s a win all the way around.”