cdj6d wetland pres

Wetland Delineation: 

Wetland Delineation Charles D. Jansen March 25, 2003 EVSC 468

Contents: 

Contents Definition Three Attributes The Process GIS Application Uses of Application Sources Pics http://www.state.nj.us/pinelands/images/wetlands.gif

Definition: 

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.”

Three Attributes: 

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.

Three Attributes: 

Three Attributes Hydrophyte Classification Indicator Category Probability Obligate wetland (OBL) > 99% Facultative wetland (FACW) 67-99% Facultative (FAC) 34-66% Facultative Upland (FACU) 1-33% Upland Plants (UPL) < 1%

The Process: 

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

Process: 

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.

Process: 

Process EPA Simple Method (cont’d) 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.

Process: 

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 1:40,000 Estuarine, Palustrine, Riverine, Lacustrine and Marine

GIS Application: 

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 1:24,000 scale maps by means of Wetland Analytical Mapping System (WAMS)

GIS Application: 

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

GIS Application: 

GIS Application The Charles D. Jansen Method of Wetland Delineation…

Slide13: 

Vegetation unioned with… …Geology.

Slide14: 

Union the two layers… …to form one layer with both attributes. 1. 2. 3.

Slide15: 

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.

Uses of Application: 

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)

Sources: 

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

Pics: 

Pics

Pics: 

Pics

Pics: 

Pics

Pics: 

Pics

The End: 

The End