Abstract
On the north coast of Ellesmere Island, streamflow occurs for only a brief period of weeks to months each year, largely in response to snowmelt. Hydrological and suspended sediment transport measurements were made in 1992 within a 21 km^2 mountainous watershed at Taconite Inlet (82° 50' N; 78° 00' W). The variability within and between time series of discharge, water temperature and suspended sediment concentration are considered at four timescales: sub-hourly, hourly, daily, and multi-day.
Sub-hourly variability was associated with slushflow activity early in the season, and demonstrates the importance of high-frequency measurements and sampling. Hourly variability followed a diurnal forcing by atmospheric energy inputs, though patterns within and between the variables were not constant through the season. Daily discharge ranged between 1500 and 241,000 m^3, and suspended sediment totals varied from less than 1 kg to 49,000 kg. On the four days of greatest sediment flux, 61 percent of the total load was transferred. During the 1992 season, four subperiods of 10 to 13 days were hydrologically delineated. Virtually all of the total sediment flux (99.8 percent) was transferred during two high discharge subperiods. These high discharge subperiods coincided with 91.9 percent of the total melting degree days for the year, demonstrating a high sensitivity of the watershed to the 0° C threshold.