Permafrost affected large rivers bed morphology: “Holes” in the bed of Kolyma river

• Main Authors: Habel, M., Sergey, C., Victor, I., Vasily, E., Damian, C., Koffi, B.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Arctic; Kolyma; Climate change; kolyma river; permafrost; Yakutia; Siberia
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5019308

The increase of water and sediment runoff in the Arctic significantly impacts the contemporary morphology of polar river channels fingerprinting climate change. This study focuses on the behaviour of non-cohesive riverbed sediments in the estuary section of the great Arctic river. We conducted a field study in the Kolyma River (Saha-Yakutia) and identified specific bed forms which form "holes" with similar depths of up to 25 - 27 m, with steep slopes with an inclination of 50° to 85°. Using field data and extended bathymetry maps, we created, calibrated and validated a high-resolute 2D morphological model. A few simulation scenarios for estimating bedform dimensions are examined to assess the ability to predict bedform parameters (length and depth) in a non-cohesive bed river. The relationship between bedform geometry (depth and the length of bedforms) and flow parameters, including shear velocity, and transport stage parameters, is investigated. The study was conducted under Trans-National Access from the European Union’s Horizon 2020 project INTERACT, under grant agreement No 730938, acronym: KolymaSed, title: “Assessment of sediment fluxes in the lower Kolyma River System, Siberia, Russia”