Sediment transport in the Tanana River in the vicinity of Fairbanks, Alaska, 1977-78

Abstract

Measurements of the sediment load of the Tanana River in the vicinity of Fairbanks, Alaska, show that suspended-sediment transport rate in tons per day, relates to water discharge, in cubic feet per second, as: Suspended-sediment transport rate (tons/day) = 5.717 x 10 to the minus 8th power x water discharge (cubic feet/second) to the 2.713 power, (where the correlation coefficient squared = 0.967). The bedload-transport rate is approximately 1 to 2 prcent of the suspended-sediment transport rate. Data collected at Fairbanks and upstream from Fairbanks near North Pole, Alaska, show little difference in size distribution of suspended sediment between the two locations. The median particle size distribution of suspended sediment is generally in the silt range, but at some low-water discharges, the median particle size is in the very fine sand range. The median particle size is in the very fine sand range. The median particle size of bedload near Noth Pole is generally in the gravel range, but at some low transport rates, the median particle size is in the medium sand range. At Fairbanks, data collected in 1977 indicate median particle sizes of bedload comparable to those of the upstream location, whereas data collected in 1978 indicate a marked decrease in median particle size of bedload between the two locations. For both locations and at all water discharges and sediment transport rates, particles constituting the suspended load are significantly smaller than particles constituting the bedload.