Subaqueous Soils A New Frontier in Soil Survey

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Subaqueous SoilsA New Frontier in Soil Survey
Visit http//nesoil.com/sas
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Background Summary

• NRCS is responsible for mapping Nations soil
  resources.
• Research has shown that soils can form under
  shallow water (submerged and subaqueous soils).
• RI NRCS strategic plan identified a gap in our
  soil data no subaqueous soils mapped.
• To begin the process of mapping our SAS we
  decided to use the MLRA concept to set up a
  special project office for subaqueous soils in
  MO-12.
• Project office proposal was sent to MO-12 Board
  of Directors and they voted to support it (with
  exception of one un-named state).
• Within RI we formed a partnership and conducted
  user conferences and began mapping a
  demonstration project to show what a SAS survey
  can provide.

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Subaqueous Soil History

• Traditional soil survey conducted on land. Not a
  lot of work in wetlands, tidal marshes, and
  coastal soils until the 70s.
• In 1993 Submerged Soils A New Frontier in Soil
  Survey by George Demas published in Soil Survey
  Horizons.
• Preliminary work in Chesapeake Bay Region -
  Maryland.
• George Demas pioneered the concept of subaqueous
  soils differentiating them from the traditional
  concept of sediment.

George Demas
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• Requirements for Soil
• Horizons formed by pedogenesis.
• and/or
• Ability to support rooted vegetation.

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Definition of Soil

• Soilis a natural body that occurs on the land
  surface, and is characterized by either
• Horizons, or layers, that are distinguishable
  from the initial material as a result of
  additions, losses, transfers, and transformations
  of energy and matter or
• The ability to support rooted plants in a natural
  environment.

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Soil Formation Soil Horizons

• Organic (O) and mineral (A and C) horizons.
• Predominantly dealing with AC type soils
  (Entisols).
• Numerous buried A and O horizons.
• Some subaqueous and submerged soils have buried B
  horizons.

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Definition of Soil

• The upper limit of soil is the boundary between
  soil and air or shallow waternot too deep
  (typically more than 2.5 m) for the growth of
  rooted plants.
• Added to Soil Taxonomy in 1999 as a result of
  work in Maryland/Delaware.

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Specific Soil Based Interpretation or Why is this
useful to humans?

• SAV Restoration
• Crab Habitat, Clam Stocking
• Management for Sustainable Production Clam,
  Oyster, and Scallop
• Nutrient Reduction
• Pathogens Pfisteria Cyst Residence Sites
• Benthic Preservation Site Identification
• Wildlife Management
• Wading Shore Birds, Migratory Waterfowl,
  Nurseries and Spawning Areas
• Habitat Protection for Horseshoe Crab and
  Diamondback Terrapin
• Dredging Island Creation
• Tidal Marsh Protection and Creation
• Bathymetric Map by-products
• Navigational Channel Creation/Maintenance
• Effects of Dredging on Benthic Ecology
• Off Site Disposal of Dredge Spoil
• Acid-Sulfate Weathering Hazards
• Dune Maintenance/Replenishment
• Baseline data for emergency planning and response.

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Mapping Partnership for Coastal Soils and
Sediment MapCoast.org

• Partnership formed to bring together groups
  involved with coastal soil and sediment mapping
  in RI.
• Steering Team.
• Hosted two user conferences.
• Developed mapping protocol and mapped Ninigret.

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Subaqueous Landforms
http//nesoil.com/sas/glossary.htm
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Problems/Considerations

• Difficult mapping conditions and procedure
  (augering in water, describing profiles, etc.).
• Need inter-discipline collaboration (coastal
  geology, marine ecology, biologist, etc.).
• Alluvial soils are very variable and subject to
  change (seasonal and long term).
• Seasonal mapping (bathymetry year round).
• Safety concerns (weather, boating,
  environmental).
• Requires some additional equipment, storage
  space, and maintenance. Need bathymetry!

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Good Aerial Imagery a MUST!
Flown at low tide.Flown with no wind.Proper
filters.Highest resolution possible.
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Conventional Mapping Tools.
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SAS Plan for the Northeast Region

• Master Plan Make RI a center for excellence in
  Subaqueous Soils.
• Internal Set up a special project office for
  MO-12 using the MLRA concept.
• External (RI) Establish a partnership of groups
  involved with coastal issues (MapCoast).
• Conduct a user workshop to determine interest in
  SAS data and obtain user input on types of data
  needed.
• Begin mapping subaqueous soils in MO-12.
• Produce a subaqueous soil survey.

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Ninigret Pond Demonstration

• Largest CP in RI (1,500 ac).
• Very important.
• Highly studied.
• Section was used for a SAS masters thesis.

Cross Mills Fan Delta
Ninigret Fan Delta
Charlestown Moraine
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Bathymetry Deliverables

• Raw depth points
• Grid (Arc Grid)
• 1 foot contours line (Arc Line Coverage)
• FGDC metadata for each

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Side-Scan Sonar

• Acoustic remote sensing.
• Can detect changes in bottom type (hard vs.
  soft).
• Gives a picture of subsurface features.
• Jons demo.

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SPI Imaging
High resolution photo of upper 20 cm of
sediment. Can be used to analyze sediment
(particle size, gas pockets, redox surface,
etc.). Used to ground-truth side scan data.
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70 images taken in Ninigret
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Other Data Collection
Video Underwater Photography Sub bottom
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Lidar
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Soil Mapping

• Entered all description in pedon program.
• Developed map unit legend.
• Located areas for obtaining full cores to
  describe and sample.
• Onscreen digitized soil polygons.
• Developed limited interpretations.

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The Coring Vessel by GSO
Obtained 2 m piston (hammer) cores and
vibra-cores.
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Vibra-Coring Techniques
Uses a gas/electric engine and a cement agitator
to vibrate aluminum tubes into the ground. Works
in sand, organics, not in till or cobbly material.
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Core Splitting, Describing, Analyzing
Cores were refrigerated, split open, and
described in detail.
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XRF Meter Heavy Metal Analysis
Rapidly and accurately measures over 15 metals,
important for baseline data and health issues.
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Point data available online
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