Seasonal Land Cover Change
Map type: Terrestrial Ecosystems
These images are clear-sky composites of land surface cover in North America during 2006. To highlight differences in land cover, a false-color composite is used: ice and snow appear in pink, dense vegetation in orange, sparser vegetation in green, and water in dark blue. Twelve separate images-one for each month in 2006-and a short animation are available. Together these images capture the effect of seasonal changes on land cover across the face of North America.
The southerly progression of snow and ice during the winter months and the re-growth of vegetation during the spring and summer months are clearly visible in this series without obstruction by clouds. Remote-sensing data for these images came from the MODIS (or Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. This satellite, part of NASA’s Earth Observing System, passes over the entire Earth’s surface every 1 to 2 days.
Each of the images in this series is a composite assembled from ten days worth of satellite observations to create a mostly cloud-free view. All images have been resampled to 2.5 kilometers per pixel from their original spatial resolution of 250 or 500 meters per pixel.
The Canada Centre for Remote Sensing of Natural Resources Canada produced these images to support the development of a North American Land Change Monitoring System (NALCMS) that will track landscape change on an annual basis.
Further analysis of these images will determine current land cover across North America and help distinguish between regular seasonal changes and land change from forces such as fires, floods, deforestation, agricultural conversion, and urbanization.
Other partners in the NALCMS include the Center for Earth Resources Observation and Science (EROS) of the US Geological Survey, Conabio (Comisión Nacional para el Conocimiento y Uso de la Biodiversidad), Conafor (Comisión Nacional Forestal), and INEGI (Instituto Nacional de Estadística, Geografía e Informática).