35 Years of Vegetation and Lake Dynamics in the Pechora Catchment, Russian European Arctic

• Published in: Remote Sensing
• Main Authors: Marinela-Adriana Cheţan, Andrei Dornik, Florina Ardelean, Goran Georgievski, Stefan Hagemann, Vladimir E. Romanovsky, Alexandru Onaca, Dmitry S. Drozdov
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: vegetation greenness; vegetation moisture; Landsat time series; remote sensing; trend analysis; permafrost; Science; Q; Arctic; Climate change; Global warming; Pechora; Pechora Delta; taiga; Tundra
• Online Access: https://doi.org/10.3390/rs12111863; https://doaj.org/article/8c297e2fe3f049e9891b004f33341838

High-latitude regions are a hot spot of global warming, but the scarce availability of observations often limits the investigation of climate change impacts over these regions. However, the utilization of satellite-based remote sensing data offers new possibilities for such investigations. In the present study, vegetation greening, vegetation moisture and lake distribution derived from medium-resolution satellite imagery were analyzed over the Pechora catchment for the last 35 years. Here, we considered the entire Pechora catchment and the Pechora Delta region, located in the northern part of European Russia, and we investigated the vegetation and lake dynamics over different permafrost zones and across the two major biomes, taiga, and tundra. We also evaluated climate data records from meteorological stations and re-analysis data to find relations between these dynamics and climatic behavior. Considering the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Moisture Index (NDMI) in the summer, we found a general greening and moistening of the vegetation. While vegetation greenness follows the evolution of summer air temperature with a delay of one year, the vegetation moisture dynamics seems to better concur with annual total precipitation rather than summer precipitation, and also with annual snow water equivalent without lag. Both NDVI and NDMI show a much higher variability across discontinuous permafrost terrain compared to other types. Moreover, the analyses yielded an overall decrease in the area of permanent lakes and a noticeable increase in the area of seasonal lakes. While the first might be related to permafrost thawing, the latter seems to be connected to an increase of annual snow water equivalent. The general consistency between the indices of vegetation greenness and moisture based on satellite imagery and the climate data highlights the efficacy and reliability of combining Landsat satellite data, ERA-Interim reanalysis and meteorological data to monitor temporal ...