Impact of the global warming on the fluvial thermal erosion over the Lena River in Central Siberia

Abstract

The hydrology of the Lena and its tributaries is characterized by an extremely episodic flow regime. Here we report recent climatic change in Central Siberia, and its impact on the fluvial thermal erosion. We point out three major changes since the 1980s: a marked reduction of the river ice thickness in winter, a pronounced increase of the water stream temperature in spring and a slight increase of the discharge during the break up (May–June). A GIS analysis based on aerial pictures and satellite images highlights the impact of the water warming on the frozen banks. The vegetated islands appear to be very sensitive to the water temperature increase, showing an acceleration of their head retreat (+21–29%). This suggests that recent global warming directly affects the fluvial dynamics and the erosional process of one of the largest arctic fluvial system.