Wetland Delineation

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Wetland Delineation

• Charles D. Jansen
• March 25, 2003
• EVSC 468

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Contents

• Definition
• Three Attributes
• The Process
• GIS Application
• Uses of Application
• Sources
• Pics

http//www.state.nj.us/pinelands/images/wetlands.g
if
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Definition

• Many definitions for wetlands
• Fish and Wildlife Service (FWS)
• Wetland are lands transitional between
  terrestrial and aquatic systems where the water
  table is usually at or near the surface or the
  land is covered by shallow water. For purposes
  of this classification, wetlands must have one or
  more of the following three attributes (1) at
  least periodically, the land supports
  predominantly hydrophytes (2) the substrate is
  predominantly undrained hydric soil and (3) the
  substrate is nonsoil and is saturated with water
  or covered by shallow water at some time during
  the growing season of each year.

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Three Attributes

• Hydrology degree of soil saturation/flooding
• Hydrophytes wetland vegetation
• Hydric Soils soil wet enough to periodically
  produce anaerobic conditions
• These attributes help to first identify and then
  determine the general location of a wetland
  compared to the surrounding uplands.

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Three Attributes

• Hydrophyte Classification
• Indicator Category Probability
• Obligate wetland (OBL) gt 99
• Facultative wetland (FACW) 67-99
• Facultative (FAC) 34-66
• Facultative Upland (FACU) 1-33
• Upland Plants (UPL) lt 1

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The Process

• Definition of wetland delineation
• The detailed examination and surveying of the
  specific boundaries of wetlands on a particular
  parcel of land. - NWI
• Various manuals on delineation.
• Corps Manual, EPA Manual, Federal Interagency
  Manual

On site delineation www.fhwa.dot.gov/environment/
strmlng/nov01nl.htm
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Process

• EPA Simple Method
• Step 1. Separate into vegetation units
• Step 2. Develop species list, estimate cover
  class, and indentify dominants
• Step 3. Modified? No OBL species dominant,
  then wetland. UPL species dominant, then
  nonwetland. FACW, FAC, or FACU species dominant,
  then next step.

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Process

• EPA Simple Method (contd)
• Step 4. Hydric soils? Yes hydrology
  indicators? No then nonwetland. Hydrology
  indicators yes then wetland.
• Step 5. Complete other vegetation units
• Step 6. Delineate upland/wetland boundary based
  on previous steps.

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Process

• Photointerpretation
• Use remote sensing such as aerial photography
• Visually notice the contrast of green and the
  texture to determine upland from wetland
• Challenges seasonal changes, cloud/snow cover,
  different scales, different wetlands
• Best time Spring (May)
• Best scale 140,000
• Estuarine, Palustrine, Riverine, Lacustrine and
  Marine

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GIS Application

• National Wetlands Inventory (NWI) procedure
• 1. Maps compiled through manual
  photointerpretation w/ Cartographic Engineering
  4X Mirror Stereoscope.
• 2. Delineated wetland boundaries manually
  transferred from photos to 7.5 min USGS
  quadrangles.
• 3. Digital wetlands data
• a. Manually digitized or
• b. Scanned from 124,000 scale maps by means of
  Wetland Analytical Mapping System (WAMS)

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GIS Application

• WAMS or geo-WAMS
• Link between Water Analysis Simulation Program
  v.4 (WASP4) and Arc/Info
• Spatial/temporal analysis of data
• Model input configuration/editing/conversion
• Model output interpretation/reporting/display
• Model calibration/confirmation/application

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GIS Application

• The Charles D. Jansen Method of Wetland
  Delineation

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Vegetation unioned with
Geology.
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Union the two layers
1.
2.
3.
to form one layer with both attributes.
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By using SQL we can isolate polygons
with attributes that meet wetland requirements
to delineate the possible locations of
wetlands seen here isolated in bright blue.
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Uses of Application

• Refuge Management
• Everglades National Park (ENP)
• Wetland Permitting
• Army Corps of Engineers (ACE)
• Wetlands Conservation
• Natural Rersource Conservation Service (NRCS) and
  Swampbuster
• Wetland Restoration Planning
• South Everglades Restoration Project (SERP)

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Sources

• Wetlands Indicators A Guide to Wetland
  Identification, Delineation, Classification, and
  Mapping by Ralph W. Tiner
• Florida Department of Environmental Protection
  http//www.dep.state.fl.us/gis/datadir.asp
• GIS Data Depot http//www.gisdatadepot.com/readme/
  nwi/nwi.html
• National Wetlands Inventory http//www.nwi.fws.gov

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Pics
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Pics
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Pics
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Pics
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The End