WERC Project Reports
http://hdl.handle.net/11122/7175
2024-03-29T11:17:36ZHydrological and Meteorological Observations on Seven Streams in the National Petroleum Reserve–Alaska (NPR–A)
http://hdl.handle.net/11122/10395
Hydrological and Meteorological Observations on Seven Streams in the National Petroleum Reserve–Alaska (NPR–A)
Vas, D.; Toniolo, H.; LaMesjerant, E.; Bailey, J.
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.
2018-09-01T00:00:00ZSagavanirktok River Particle Size Distributions
http://hdl.handle.net/11122/10394
Sagavanirktok River Particle Size Distributions
Tape, Ken; Clark, Jason; Toniolo, Horacio
2017-10-01T00:00:00ZHydrological, Sedimentological, and Meteorological Observations and Analysis on the Sagavanirktok River
http://hdl.handle.net/11122/10393
Hydrological, Sedimentological, and Meteorological Observations and Analysis on the Sagavanirktok River
Toniolo, H.; Youcha, E.K.; Tape, K.D.; Paturi, R.; Homan, J.; Bondurant, A.; Ladines, I.; Laurio, J.; Vas, D.; Keech, J.; Tschetter, T.; LaMesjerant, E.
The Dalton Highway near Deadhorse was closed twice during late March and early April 2015
because of extensive overflow from the Sagavanirktok River that flowed over the highway. That
spring, researchers from the Water and Environmental Research Center at the University of
Alaska Fairbanks (UAF) monitored the river conditions during breakup, which was characterized
by unprecedented flooding that overtopped and consequently destroyed several sections of the
Dalton Highway near Deadhorse. The UAF research team has monitored breakup conditions at
the Sagavanirktok River since that time. Given the magnitude of the 2015 flooding, the Alyeska
Pipeline Service Company started a long-term monitoring program within the river basin. In
addition, the Alaska Department of Transportation and Public Facilities (ADOT&PF) funded a
multiyear project related to sediment transport conditions along the Sagavanirktok River. The
general objectives of these projects include determining ice elevations, identifying possible water
sources, establishing surface hydro-meteorological conditions prior to breakup, measuring
hydro-sedimentological conditions during breakup and summer, and reviewing historical
imagery of the aufeis extent. In the present report, we focus on new data and analyze it in the
context of previous data.
We calculated and compared ice thickness near Franklin Bluffs for 2015, 2016, and 2017, and
found that, in general, ice thickness during both 2015 and 2016 was greater than in 2017 across
most of the study area. Results from a stable isotope analysis indicate that winter overflow,
which forms the aufeis in the river area near Franklin Bluffs, has similar isotopic characteristics
to water flowing from mountain springs.
End-of-winter snow surveys (in 2016/2017) within the watershed indicate that the average snow
water equivalent was similar to what we observed in winter 2015/2016. Air temperatures in May
2017 were low on the Alaska North Slope, which caused a long and gradual breakup, with peak
flows occurring in early June, compared with mid-May in both 2015 and 2016. Maximum
discharge measured at the East Bank station, near Franklin Bluffs was 750 m3/s (26,485 ft3/s) on
May 30, 2017, while the maximum measured flow was 1560 m3/s (55,090 ft3/s) at the same
station on May 20, 2015. Available cumulative rainfall data indicate that 2016 was wetter than
2017.
ii
In September 2015, seven dry and wet pits were dug near the hydro-sedimentological monitoring
stations along the Sagavanirktok River study reach. The average grain-size of the sediment of
exposed gravel bars at sites located upstream of the Ivishak-Sagavanirktok confluence show
relatively constant values. Grain size becomes finer downstream of the confluence.
We conducted monthly topo-bathymetric surveys during the summer months of 2016 and 2017
in each pit. Sediment deposition and erosion was observed in each of the pits. Calculated
sedimentation volumes in each pit show the influence of the Ivishak River in the bed sedimenttransport
capacity of the Sagavanirktok River. In addition, comparison between dry and wet pit
sedimentation volumes in some of the stations proves the complexity of a braided river, which is
characterized by frequent channel shifting
A two-dimensional hydraulic model is being implemented for a material site. The model will be
used to estimate the required sediment refill time based on different river conditions.
2017-12-01T00:00:00ZSagavanirktok River Spring Breakup Observations 2016
http://hdl.handle.net/11122/10392
Sagavanirktok River Spring Breakup Observations 2016
Toniolo, H.; Tape, K.D.; Tschetter, T.; Homan, J.W.; Youcha, E.K.; Vas, D.; Gieck, R.E.; Keech, J.; Upton, G.
In 2015, spring breakup on the Sagavanirktok River near Deadhorse was characterized by high
flows that destroyed extensive sections of the Dalton Highway, closing the road for nearly 3
weeks. This unprecedented flood also damaged infrastructure that supports the trans-Alaska
pipeline, though the pipeline itself was not damaged. The Alaska Department of Transportation
and Public Facilities (ADOT&PF) and the Alyeska Pipeline Service Company made emergency
repairs to their respective infrastructure.
In December 2015, aufeis accumulation was observed by ADOT&PF personnel. In January
2016, a research team with the University of Alaska Fairbanks began monitoring and researching
the aufeis and local hydroclimatology. Project objectives included determining ice elevations,
identifying possible water sources, establishing surface meteorological conditions prior to
breakup, measuring hydrosedimentological conditions (discharge, water level, and suspended
sediment concentration) during breakup, and reviewing historical imagery of the aufeis feature.
Ice surface elevations were surveyed with Global Positioning System (GPS) techniques in late
February and again in mid-April, and measureable volume changes were calculated. However,
river ice thickness obtained from boreholes near Milepost 394 (MP394) in late February and
mid-April revealed no significant changes. It appears that flood mitigation efforts by ADOT&PF
in the area contributed to limited vertical growth in ice at the boreholes. End-of-winter snow
surveys throughout the watershed indicate normal or below normal snow water equivalents
(SWE 10 cm). An imagery analysis of the lower Sagavanirktok aufeis from late winter for the
past 17 years shows the presence of ice historically at the MP393–MP396 area.
Water levels and discharge were relatively low in 2016 compared with 2015. The mild breakup
in 2016 seems to have been due to temperatures dropping below freezing after the flow began.
Spring 2015 was characterized by warm temperatures throughout the basin during breakup,
which produced the high flows that destroyed sections of the Dalton Highway.
A comparison of water levels at the East Bank Station during 2015 and 2016 indicates that the
2015 maximum water level was approximately 1 m above the 2016 maximum water level.
ii
Maximum measured discharge in 2016 was approximately half of that measured in 2015 in the
lower Sagavanirktok River. Representative suspended sediment sizes (D50) ranged from 20 to 50
microns (medium to coarse silt).
An objective of this study was to determine the composition and possible sources of water in the
aufeis at the lower Sagavanirktok River. During the winter months and prior to breakup in 2016,
overflow water was collected, primarily near the location of the aufeis, but also at upriver
locations. Simultaneously possible contributing water sources were sampled between January
and July 2016, including snow, glacial meltwater, and river water. Geochemical analyses were
performed on all samples. It was found that the overflow water which forms the lower
Sagavanirktok aufeis is most similar (R2 = 0.997) to the water that forms the aufeis at the
Sagavanirktok River headwaters (Ivishak River), thought to be fed by relatively consistent
groundwater sources.
2016-12-01T00:00:00Z