Hyporheic and Parafluvial Zones in

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Hyporheic and Parafluvial Zones in
The Arctic Tundra!
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The hydraulic characteristics and geochemistry of
hyporheic and parafluvial zones in Arctic tundra
streams, north slope, Alaska

• Edwarson et al. (2003) Advances in Water
  Resources

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• Purpose Investigate the hydrologic and chemical
  dynamics of hyporheic and parafluvial zones in
  Arctic tundra streams
• Importance Essentially no information on Arctic
  streams
• First comprehensive description of hyporheic and
  parafluvial zones in Arctic tundra streams
• Continuous permafrost
• Limit the importance of hyporheic processes?

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Scope of Work

• 17 conservative tracer additions on 7 streams
  from 1994-1996
• Stream reaches varied greatly
• Characterize in-stream hydrologic parameters
  using hyporheic samplers and OTIS-P simulations
• Biogeochemical and nutrient processing in
  hyporheic and parafluvial zones

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Background Definitions and Key Concepts

• Transient storage zones
• Parafluvial
• Beaded stream
• Importance of hyporheic and parafluvial zones
• 3 key factors that control water movement in
  these zones
• DO in the hyporheic zone
• Modeling limitations

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Study Area
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Study Area Kuparuk R. and Oksrukuyik Cr.
fertilized Kupa
Kupa
Mouth Of Kupa
Oks
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Whole Lotta Methods

• Hyporheic Samplers
• Tracer Additions
• Conservative Tracer Analysis
• Solute Modeling
• Vertical Hydraulic Gradient (VHG)
• Nutrient Chemistry

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Results OTIS Modeling

• No significant relationship between As/A and
  discharge
• General relationship held true
• Average storage zone cross-sectional area of the
  Arctic streams
• 43 (Range 8 254)
• 32 (Range 8 112) without Imnavait Cr.

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ResultsChannel, Upwelling, and Downwelling
Sites
Transient Storage Zones
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Results Channel, Upwelling, and Downwelling
Sites
Bottom of Riffle
Top of Riffle
Parafluvial
Tracer Penetration
Hyporheic
Hyporheic
Parafluvial
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Results Channel, Upwelling, and Downwelling
Sites
Water Quality
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Results VHG and Temperature
VHG
Parafluvial zones in left and right point bars
Riffle
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Results Benthic Uptake
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Key Discussion Points and Conclusions

• Transient storage in Arctic Streams
• Similarity to temperate regions
• As/A relationship not signifcant
• ?morphology and ?stage height are boss.
• Importance of eddies
• BUT hyporheic storage still muy importante!
• Biogeochemical importance of hyporheic flowpath.

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Key Discussion Points and Conclusions

• Permafrost
• Hyporheic flow not limited by permafrost in
  ice-free season
• Spring ice-out (thaw) may results in much lower
  As/A values due to high snow-melt Q and reduced
  interstitial area
• Water Quality
• Interstitial waters served as sources of NO3,
  NH4, PO4, and CO2
• Interstitial temperature inversely related to VHG
  and residence time in hyporheic and parafluvial
  zones.

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Questions?
NO QUESTIONS