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Fluvial thermal erosion investigations along a rapidly eroding river bank: application to the Lena River (central Siberia)
Author(s) -
Costard F.,
Dupeyrat L.,
Gautier E.,
CareyGailhardis E.
Publication year - 2003
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.592
Subject(s) - erosion , fluvial , hydrology (agriculture) , geology , bank erosion , thermal , bank , channel (broadcasting) , heat transfer , geomorphology , geotechnical engineering , meteorology , mechanics , geography , engineering , structural basin , electrical engineering , physics
In Central Yakutia, frozen river banks are affected by a combination of thermal and mechanical erosion. Exceptional bank retreat of up to 40 m per year is observed. This results from ground thawing produced by heat transfer from the ow of water through the frozen ground, followed by mechanical transport of the thawed sediments. A one‐dimensional model is proposed to estimate the thermal erosion efciency. A test of this model is a comparison of results obtained from experiments carried out in a cold room. A hydraulic channel allows measurements of the thaw front propagation, as well as the thermal erosion rate, in simulated ground ice that is subjected to warm water ow. Various laboratory simulations demonstrate the validity of the mathematical model for the range of laboratory conditions. A hierarchy of parameters (Reynolds number, water and ground ice temperatures) is proposed to explain the present efciency of thermal erosion along the Siberian rivers. From the characteristics of the Lena River (geometry, temperature and discharge) during the ood season, the erosion of banks with different ice content predicted by the model is in agreement with eld observations. Copyright © 2003 John Wiley & Sons, Ltd.