Home – Home – Jornals – Earth’s Cryosphere 2021 number 5

Interferometric pairs of ALOS PALSAR dataset (2007-2010) were used to estimate the seasonal and long-term variations in the ground surface height in the piedmont of the Polar Ural, the far northeast of European Russia. The obtained results were validated by ground-truth measurements at the CALM R2 site (the site of monitoring the thickness of the active layer). The values and amplitude of ground surface height variations obtained from the satellite imagery were lower compared to field measurements. The sites under study were classified in two conditional groups: more drained sites (confined often to the upper parts of the moraine ridges) and sites with higher moisture content in the soil (lower parts of the slopes). This classification was based on the intensity of seasonal changes in the height of ground surface during the vegetation period of 2007. Significant correlations between the compared in situ and remote sensing-based measurements were established for these groups. The convergence of the results increased with a greater number of in situ measurements inside the pixel of the satellite image. The greatest differences in the magnitude of changes in the height of ground surface were reported in years marked by contrasting weather conditions (2007 and 2010). Ground surface subsidence was reported to be greater (up to 1.5-4.5 cm) during the colder and wetter vegetation period of 2010, and less pronounced in a drier and warmer season of 2007 (0.0-3.0 cm) within tundra zones of the Pechora Lowland. A summer ground surface heave was noted (up to 2-3 cm) in sites with moraines deposits in the piedmont plains for the whole period of observations.