• Hydrological and Meteorological Observations on Seven Streams in the National Petroleum Reserve–Alaska (NPR–A)

      Vas, D.; Toniolo, H.; LaMesjerant, E.; Bailey, J. (2018-09)
      This report summarizes the hydrological and meteorological data collected from 2003 to 2017 at 7 stations in the National Petroleum Reserve–Alaska. During an 8-year period, from May 2010 to December 2017, a research team from the University of Alaska Fairbanks, Water and Environmental Research Center, and personnel from the Bureau of Land Management performed 351 discharge measurements and collected and analyzed data on air temperature, rainfall, wind speed, and wind direction at stations distributed on a southwest–northeast transect from the foothills of the Brooks Range to the Arctic Ocean. In general, the air temperature data indicate an evident warming trend for the entire region. Rainfall data suggest a trend in increasing precipitation during the summer months from the coastal plain to the foothills, though there are some exceptions. The overall highest mean monthly wind speed was recorded in February; the overall lowest mean monthly wind speed varied from station to station. Wind roses indicate two main wind directions—approximately from the northeast and southwest—with winds from the northeast predominant at the northern stations and winds from the southwest predominant at the southern stations.
    • Monitoring Winter Flow Conditions on the Ivishak River, Alaska

      Toniolo, Horacio; Vas, D.; Keech, J.; Bailey, J. (Center for Environmentally Sustainable Transportation in Cold Climates, 2017-09)
      The Sagavanirktok River, a braided river on the Alaska North Slope, flows adjacent to the trans-Alaska pipeline for approximately 100 miles south of Prudhoe Bay. During an unprecedented flooding event in mid-May 2015, the pipeline was exposed in an area located approximately 20 miles south of Prudhoe Bay. The Ivishak River is a main tributary of the Sagavanirktok River, but little is known about its water flow characteristics and contribution to the Sagavanirktok River, especially in winter and during spring breakup. To gather this information, we installed water level sensors on two main tributaries of the Ivishak River (Upper Ivishak and Saviukviayak rivers), early in winter season 2016–2017, in open-water channels that showed promise as locations for long-term gauging stations. Our ultimate goal was to find a location for permanent deployment of water level sensors. By February, the first sites chosen were ice covered, so two additional sensors, one on each river, were deployed in different locations. Some of the sensors were lost (i.e., carried away by the current or buried under a thick layer of sediments). Water level data gathered from the sensors showed a maximum change of 1.07 m. Winter discharge measurements indicate a 44% reduction between February and April 2017. A summer discharge measurement shows a 430% increase from winter to summer.