The development of river banks is conditioned by a fewfactors: fluvial erosion, mass movements and subaerial processes. Many
researchers believe that the subaerial phenomena are more preparatory
processes to actual erosion than the erosion itself. Among the subaerial
phenomena, freezing and thawing play a key role. Multigelation affects
the stability and sustainability of river banks, not only in the northern
reaches of Eurasia and North America but also in temperate latitudes.
Susceptibility to change in bank morphology, however, is extremely
selective. Within the same layer, at a distance of 1 metre the intensity of
frost erosion can be very different. This is the result of many factors
determining the rate of bank retreat. These include: the height of the
bank, its structure and texture, physical and chemical properties of the
material from which it is built, environmental conditions, soil moisture,
water pressure in the pore spaces, porosity and density of the soil,
organic matter content in the soil, temperature, vegetation, as well as
thickness and duriation of snow cover. An important objective is therefore
to show the differences in the rate of retreat of the river banks, and
above all characterized by varying degrees of density and grain size of the
material it is built of.
Keywords:
multigelation, frost action, needle ice, bank retreat