Concerns and Needs related to Alaska Coastal Infrastructure

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Concerns and Needs related to Alaska Coastal
Infrastructure

• Orson P. Smith, PE, Ph.D.

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Alaskan Engineers' Viewsof Global Warming
Challenges

• Proven responses to most warming problems exist
• Accurate prediction of changes will save money
• Existing data needs to be synthesized
• Statewide monitoring is warranted
• Data and technology transfer can be improved
• Need revised design codes, manuals, and software

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Sea Level Rise Other Trends in Alaska Complicate
Predictions
Intergovernmental Panel on Climate Change, 2001
?
Figures from EPA website http//www.epa.gov/global
warming/
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Permafrost Coasts

• Permafrost changes
• Thaw subsidence, onshore and offshore
• Increased flux of sediments into streams and the
  coastal ocean

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Permafrost foundations at risk

• About 90,000 Alaskans live in permafrost areas
• 21 of Alaskas road miles are on continuous
  permafrost
• 57 road miles are on discontinuous permafrost
• All Beaufort Chukchi Sea and much of Bering Sea
  coastal infrastructure is on permafrost

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Coastal communities at risk

• Sea level rise (0.1 0.9 m
  by 2100)
• Flooding
• Erosion
• Salt intrusion
• More frequent and intense storms (maybe)
• Reduced ice cover (yes!)
• More surges
• More wave energy
• Coastal erosion may make some communities
  untenable
• A baseline of Alaska coastal conditions does not
  exist

Shishmaref
Little Diomede, Alaska
Little Diomede
Kivalina
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Sea Ice Changes

• Lesser sea ice extent, thickness, and duration
• More open water over longer periods
• Longer fetches and higher waves at the coast

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Anticipated Changes in Streamflow

• More rainfall in winter
• Increased winter runoff
• Mid-winter breakups
• Mid-winter ice jams
• Accelerated thawing of permafrost banks
• Accelerated bank erosion
• Higher sediment loads to coast

Alaska Ice Jams
Cold Regions Research Engineering Laboratory
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Bridge and culvert problems
MP 228 Richardson Highway One Mile Creek Bridge
photo provided by George Levasseur, Alaska
Department of Transportation Public Facilities
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Marine transportation benefits

• River Transportation
• Flow increases could improve commercial river
  navigability
• Ocean Transportation
• Less ice
• New northern ports

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Southcentral Alaska coastal issues
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Cook Inlet Bluff Erosion
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Cook Inlet Bluff Erosion
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Homer Spit from about 2 miles
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Eroding bluffs NW of Homer Spit
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Role of tidal currents?
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Opportunities for public professional education
in Alaska
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UAA School of EngineeringPort Coastal
Engineering Courses

• CE A674 Waves, Tides, Ocean Processes
• CE A675 Design of Ports Harbors
• CE A676 Coastal Engineering
• CE A677 Coastal Measurements and Analysis
• GIS A333 Marine Applications of GIS
• GE0 A433 Hydrographic Surveying
• by televideo with UAF and UAS

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UAA and UAFArctic Engineering MS Programs

• CE A603 Arctic Engineering
• CE A681 Frozen Ground Engineering
• CE A682 Ice and Snow Engineering
• CE A683 Arctic Hydrology Hydraulic Engineering
• CE A684 Arctic Utilities
• ME A685 Arctic Heat Mass Transfer
• ME A687 Arctic Materials
• UAA required course

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Existing Alaska Coastal Research Programs

• NOAA Alaska Sea Grant College Program
• Research topics aligned with National and State
  Sea Grant priorities
• Includes extensive public outreach capability
  (Marine Advisory Program)
• MMS Alaska Coastal Marine Institute
• Research topics aligned with MMS-Alaska priorities

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Alaska littoral baseline assessment- an
opportunity for interagency collaboration

• Locate present shoreline
• Tidal datum? Ellipsoid standard? Bluff shores?
  Sea level change? Tectonic change? Permafrost
  thaw subsidence?
• Define littoral cells
• By longshore sediment sources and sinks
• By wave exposure
• By tide and tidal current regime
• Quantify longshore sediment transport
• Quantify rates of coastal sediment supply (e.g.,
  rivers and bluffs) and loss (to offshore sinks)

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Improve measurement and modeling of fjord wind
and wave relationships

• e.g., 10 March 2005 storm at Whittier
• Orographic funneling of winds difficult to
  quantify
• Fetch-limited predictions are not conservative

Photo provided by Sandra Morris, PND, Inc.
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Improve design of erosion control responses in
high tide ranges and cold climates

• Emphasize tech transfer and public outreach
• Develop guidance for assessing wave and tidal
  current interaction

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