Short-term discharge and suspended sediment fluctuations in the proglacialSkeldal River, north-east Greenland

The summer discharge pattern of the Skeldal River, which drains a 560 km(2) partly glacierized catchment in northeast Greenland, is dominated by diurn al oscillations reflecting variations in the melt rate of snow and ice in t he basin. Superimposed on this diurnal pattern are numerous short-lived dis charge fluctuations of irregular periodicity and magnitude. The larger fluc tuations are described and attributed to both rainfall events and periodic collapse of the glacier margin damming flow from beneath the Skelbrae glaci er. Other minor fluctuations are less readily explained but are associated with changes in the channelized and distributed reservoirs and possibly tem porary blockage of subglacial conduits caused by ice melt with subsequent d amming. Fluctuations in suspended sediment concentration (SSC) are normally associa ted with discharge fluctuations, although examples of 'transient flushes' w ere observed where marked increases in SSC occurred in the absence of corre sponding discharge variations. A strong relationship between the event disc harge increase and event SSC increase for rainfall-induced events was estab lished, but no such relationship existed for non-rainfall-induced events. T here is some evidence for an exhaustion effect in the SSC patterns both at the event time-scale and as the month proceeds. A mean suspended sediment l oad of 1765 +/- 0.26 t day(-1) was estimated for the study period, which wo uld be equivalent to a suspended sediment yield of 732 +/- 4 t km(-2) year( -1). Copyright (C) 2001 John Wiley & Sons, Ltd.