Suchergebnisse

Remote sensing of Arctic water bodies is an essential method for monitoring the dynamics of frozen ground. Thaw lake change provides insight into the state of permafrost. In the vast Arctic and sub-Arctic areas capturing changes in lake extent is assisted by satellite data. In particular, active microwave sensors can be used in a straightforward manner for water body classifications. This study uses the pan-Siberian datasets that are provided under the ESA STSE-ALANIS methane project. Surface water classifications in 10-day intervals have been produced using Envisat ASAR (Advanced Synthetic Aperture Radar) operating in wide swath mode. The high temporal frequency of these data allows an investigation of surface hydrology on an intra-annual basis. The current study applies a post-processing algorithm to the ALANIS products in order to investigate changes in surface inundation across the Yamalo-Nenets Autonomous District over the summer period of 2007. Multiple areas are found to exhibit changes in surface inundation. Strong seasonal variations occur in areas where previous investigations determined disappearing lakes. Spring floods associated with the depletion of snow-cover and melt waters as well as floodplain dynamics can be identified. On the Yamal peninsula, these changes occur most dominantly in the west; an area subject to anthropogenic land-use change. Changes in water body extent for each hot spot of seasonal variations are quantified and discussed. ; European Space Agency (ESA) Support to Science Element (STSE) programme (ESRIN) ; the European Union FP7-ENV ; Austrian Science Fund (FWF)