Fluvial Sediment Transfer in Cold Regions

Abstract

The fluvial signature of sedimentary disturbance can be likened to the response of a cascade of linear reservoirs, at least qualitatively. The reservoirs are fluvial landforms, including channel deposits. The signature includes contemporaneous degradation and aggradation at different places in the landscape. The most significant fluvial disturbance to have affected terrestrial landscapes in recent earth history is recurrent, unstable continental glaciation in the Northern Hemisphere. Successive glaciations yielded major fluvial disturbances, the residual effects of which are still detectable in undisturbed landscapes. However, the fluvial response to glaciation, which may be termed the ‘paraglacial response’ is similar to the response to other sedimentary disturbances. In most places, residual paraglacial effects are now overwhelmed by other, more recent fluvial disturbances, in particular the effects of human land use. Complications of the conceptual model include the variable mobility of sediments of different calibre and the superimposition of various disturbances. There are few data to allow quantitative analysis of the model, but it presently serves to indicate aspects of fluvial sediment transport and storage that require attention in order to improve our understanding of fluvial sediment transfer in the landscape.