Hyporheic and Parafluvial Zones in… The Arctic Tundra!

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

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?

Scope of Work 17 conservative tracer additions on 7 streams from –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

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

Study Area

Study Area: Kuparuk R. and Oksrukuyik Cr. Kupa fertilized Kupa Mouth Of Kupa Oks

Whole Lotta Methods: Hyporheic Samplers Tracer Additions Conservative Tracer Analysis Solute Modeling Vertical Hydraulic Gradient (VHG) Nutrient Chemistry

Results: OTIS Modeling No significant relationship between A s /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.

Results: Channel, Upwelling, and Downwelling Sites Transient Storage Zones

Results: Channel, Upwelling, and Downwelling Sites Tracer Penetration Hyporheic Parafluvial Hyporheic Parafluvial Bottom of RiffleTop of Riffle

Results: Channel, Upwelling, and Downwelling Sites Water Quality

Results: VHG and Temperature VHG Riffle Parafluvial zones in left and right point bars

Results: Benthic Uptake

Key Discussion Points and Conclusions Transient storage in Arctic Streams –Similarity to temperate regions A s /A relationship not signifcant –Δmorphology and Δstage height are boss. –Importance of eddies BUT hyporheic storage still muy importante! –Biogeochemical importance of hyporheic flowpath.

Permafrost –Hyporheic flow not limited by permafrost in ice-free season –Spring ice-out (thaw) may results in much lower A s /A values due to high snow-melt Q and reduced interstitial area Water Quality –Interstitial waters served as sources of NO 3, NH 4, PO 4, and CO 2 –Interstitial temperature inversely related to VHG and residence time in hyporheic and parafluvial zones. Key Discussion Points and Conclusions

Questions? NO QUESTIONS