Hydraulic Characteristics and Suspended Sediment Loads during Spring Breakup in Several Streams Located on the National Petroleum Reserve in Alaska, USA

Abstract

This article presents results from a broad field campaign involving discharge and surface-water slope measurements, water sampling, and longitudinal river-bed profile surveys. During the spring breakup of 2011, fieldwork was carried out in several pristine streams located in the National Petroleum Reserve in Alaska; the studied streams cover two main regions: 1) foothills (Ikpikpuk River, Seabee Creek, Prince Creek, and Otuk Creek); 2) coastal plain (Fish Creek, Judy Creek, and Ublutuoch River). Reported data includes basic geometric and hydraulic characteristics such as channel width and depth, cross-sectional area, average velocity, friction factor, shear stress, suspended sediment concentrations from autosamplers and grab samples, and dune dimensions and steepness ratios. The measured discharge in different streams ranged from 2 to 853 m3/s, which corresponded to post-breakup and near peak conditions, respectively. The temporal variation of Manning’s n was in phase with measured discharge, with high values of n associated with the presence of floating ice during the measurements. Calculations indicate that sediment particle sizes ≤2 mmmoved during the measurements. In general, variations in discharge were accompanied by changes in suspended sediment concentrations.