Regional North American AVHRR NDVI disturbances classified in Landsat: 1982-2003

To investigate land cover land use change across North America, we used the Global Inventory Modeling and Mapping Studies (GIMMS) Advanced Very High Resolution (AVHRR) Normalized Difference Vegetation Index (NDVI) data from the NOAA series of polar orbiting satellites over the period of 1982 to 2005. NDVI anomalies were generated over the time periods 1982-1991, 1992-2003, and 1982-2003 to determine changes in vegetation cover. Anomaly areas were then investigated with Landsat multi-spectral data and classified into the international geosphere biosphere program (IGBP) classes of vegetation cover types including: needle leaf evergreen, mixed needle leaf evergreen and broad leaf deciduous, broad leaf deciduous, dwarf trees and shrubs, short vegetation C4 grassland, active and fallow agriculture C3 grasslands. Extensive logging was found in the Canadian province of Quebec. Recovery from large boreal fires was discovered in Saskatchewan, and changes in agricultural production practices were found in the Midwest. Quantification of land cover changes on a regional basis over the past 23 years revealed human and natural disturbance impacts, which may impart significant carbon consequences when accounting North American sinks and sources.