Glacial Effects on Discharge and Sediment Load in the Subarctic Tanana River Basin, Alaska

• Published in: Arctic, antarctic, and alpine research Vol. 43; no. 4; pp. 632 - 648
• Main Authors: Wada, Tomoyuki, Chikita, K. A, Kim, Y, Kudo, I
• Format: Journal Article
• Language: English
• Published: UCB 450, University of Colorado, Boulder, Colorado 80309-0450, U.S.A The Institute of Arctic and Alpine Research 01.11.2011; Taylor & Francis; Institute of Arctic and Alpine Research; University of Colorado, Institute of Arctic and Alpine Research
• Subjects: Alpine glaciers; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Glacial melting; Glaciers; Precipitation; River basins; Sediment yield; Sediments; Stormwater; Surface runoff; Suspended solids; Synecology; Alaska; United States; North America; America; USA, Alaska, Chena R; Canada, Yukon Terr., Yukon R. basin; USA, Alaska, Tanana R; PN, Arctic; USA, Alaska; Load; Tanana River; Subpolar zone; Sediments; River basins
• ISSN: 1523-0430; 1938-4246
• DOI: 10.1657/1938-4246-43.4.632

About 5.6% of the drainage area of the Tanana River, Alaska, is covered by mountainous glacierized regions, and most of the other area by forests (51%) and wetlands (9%) with discontinuous permafrost. The water discharge and sediment load from glacierized and non-glacierized regions within the drainage area were represented by observed data of the proglacial Phelan Creek and the non-glacial Chena River, respectively, which are both the tributaries of the Tanana River and ultimately drain to the Yukon river basin. In the glacier-melt periods of 2007 and 2008, the runoff rate and suspended sediment concentration in Phelan Creek was 15 times and 36 times as high as those in the non-glacial Chena River, respectively. As a result, the mean sediment yield in the glacier-melt periods of 2007 and 2008 for Phelan Creek (24.8 t km−2 day−1) was estimated to be 640 times as high as that in the Chena River (0.039 t km−2 day−1). Hence, the glacierized regions were considered to be a major source of the fluvial sediment. In order to quantify the contribution of water discharge and sediment load from the glacierized regions to those of the Tanana River, the time series of water discharge, Q, and sediment load, L, in the glacier-melt periods were simulated by a tank model coupled with the L-Q equations (Nash-Sutcliffe efficiency coefficients, 0.41 to 0.82). The model indicates that the glacier-melt discharge accounted for 26–57% of the Tanana discharge, while the sediment load from the glacierized regions solely accounted for 76–94% of the Tanana sediment load. The remaining contribution (6–24%) of the sediment load was probably due to the fluvial resuspension of glacial sediment deposited previously in the river channels.