CLIMATIC VARIABILITY, CLIMATIC CHANGE, RUNOFF, AND SUSPENDED SEDIMENT REGIMES IN NORTHERN CANADA

Streamflow and sediment concentrations in northern rivers are highly variable from year to year, but the paucity of data renders it difficult to establish the norms of contemporary water and sediment discharges. With regard to suspended sediment yield, nival, proglacial, and prolacustrine regimes are recognized, depending on the sources of water and the sources and sinks of sediments in the streams. The availability of water and sediments is often asynchronous, particularly because of the presence of snow and ice in the channel and permafrost in the banks, which play both protective and enhancement roles in fluvial erosion, depending on the season. Thus, empirical relationships between sediment concentrations and streamflow may be highly tenuous.