Trends of land surface change from Landsat time-series 1999-2014

Changes can be gradual (press disturbance) or rapid (pulse disturbances). Press disturbances are gradual changes in land cover such as shrub expansion, wetting, drying, and active layer deepening.

Pulse disturbances are rapid changes such as thermokarst and thermo-erosion, lake formation, expansion, and shrinkage, erosion, and wildfires. The HRPC products provide trends of multi-spectral indices such as Tasselled Cap brightness, greenness, wetness and normalized indices (NDVI, NDWI, NDMI) in 4 regional transects spanning the panarctic permafrost domain. HRCP maps are available for four transects: T1 Western Siberia, T2 Eastern Siberia, T3 Alaska, and T4 Eastern Canada.