January 2002

Wetland Types, Functions, and DCM’s GIS

Wetland Data

North Carolina Department of Environment and Natural Resources

Division of Coastal Management

January 2002

DCM GIS Wetland Data:• Wetland Type Data

• Wetland Functional Significance Data

• Potential Wetland Restoration and Enhancement Site Data

• Wetland Restoration Site Functional Significance Data (in progress)

January 2002

• WetlandsWetlands• Wetland FunctionsWetland Functions• Wetland TypesWetland Types• GIS Wetland DataGIS Wetland Data• NC-CREWS DataNC-CREWS Data• Getting DCM’s DataGetting DCM’s Data

Topics

January 2002

Wetlands Wetlands

Wetlands are areas that are Wetlands are areas that are periodically or permanently inundated periodically or permanently inundated by surface or ground water and by surface or ground water and support vegetation adapted for life in support vegetation adapted for life in saturated soil. Wetlands include saturated soil. Wetlands include swamps, marshes, bogs and similar swamps, marshes, bogs and similar areas.areas.

January 2002

What do wetlands do?What do wetlands do?

Wetland FunctionsWetland Functions

HabitatHabitat nesting, spawning, rearing and resting nesting, spawning, rearing and resting sites for sites for aquatic and land species, food aquatic and land species, food chain productionchain production

HydrologyHydrology protection of other areas from wave protection of other areas from wave action and action and erosion, storage areas for storm erosion, storage areas for storm water and water and flood water, ground and flood water, ground and surface water aquifer surface water aquifer recharge recharge

Water Water water water quality protection, water quality protection, water filtration and filtration and QualityQuality purification, treatment of purification, treatment of nonpoint nonpoint source runoff source runoff

January 2002

• maintain biodiversitymaintain biodiversity

• provide habitat for animals provide habitat for animals

• maintain water qualitymaintain water quality

• support commercial support commercial fishing, fishing, forestryforestry

• reduce flood damage reduce flood damage

• hiking, fishing, hunting, hiking, fishing, hunting, bird watching, boatingbird watching, boating

• aesthetic valueaesthetic value

Why are wetlands Why are wetlands important?important?

Wetland ValuesWetland Values

Did you know?Did you know?

Nationwide, an estimated 50 million people spend Nationwide, an estimated 50 million people spend approximately $10 billion annually observing and approximately $10 billion annually observing and photographing wetland-dependent birds.photographing wetland-dependent birds.

January 2002

There are many different There are many different kinds of wetlands.kinds of wetlands.

People place different People place different values on them based on values on them based on

the functions they the functions they perform.perform.

January 2002

Where are wetlands located?Where are wetlands located?

• Wetlands are located throughout NC Wetlands are located throughout NC

• There are two kinds of maps in NC There are two kinds of maps in NC that show the locations and types of that show the locations and types of wetlands:wetlands:

1.1. National Wetland Inventory (NWI) MapsNational Wetland Inventory (NWI) Maps

2.2. DCM Wetland Type MapsDCM Wetland Type Maps

January 2002

Example of National Wetland Inventory (NWI) Map

NWI maps show many different wetland types

January 2002

P F O 4 What?

The U.S. Fish & Wildlife Service’s National Wetland Inventory (NWI) uses what is called the Cowardin Classification to classify wetlands. This classification system is used by scientists and resource managers nationwide. This complex system can be difficult for the average user to interpret.

January 2002

DCM’s wetland maps are easy to understand

because wetlands are grouped into well-known

categories.

January 2002Example: DCM Wetland Type Map

DCM’s maps show 13 wetland types

January 2002

DCM’s GIS Wetland Type Data

Show the location, type, and amount of wetlands in the North Carolina Coastal Plain

January 2002

DCM’s GIS Wetland Type Datauses these primary GIS layers

• National Wetland Inventory (NWI) Maps

• NRCS Digital Soils Maps

• Satellite Imagery - 1988, 1994

• Hydrography

January 2002

January 2002

DCM Wetland Classification

DCM Wetland Types:•Swamp Forest•Bottomland Hardwood•Pocosin•Pine Flat•Hardwood Flat•Managed Pine•Freshwater Marsh•Salt/Brackish Marsh•Estuarine Scrub Shrub•Estuarine Forest•Maritime Forest•Headwater Swamp•Human Impacted

Modifiers:Partially Drained/ Ditched

Cut-over

Cleared

January 2002

DCM Wetland Classification

Hydrogeomorphic Classification (HGM):

This classification describes the hydrology and the geomorphic setting of a wetland

•Riverine•Flat or non-riverine•Tidal

January 2002

The following slides show photos of wetland types typically found in Coastal

North Carolina.

January 2002

Riverine Swamp Forest

January 2002

Headwater Swamp

January 2002

Swamp Forest

January 2002

Pocosin Wetland

January 2002

Hard Wood Flat

Wet Pine Flat

January 2002

Tidal Salt Marsh

January 2002

Are DCM’s GIS Wetland Maps Accurate?

January 2002

Accuracy Assessment

• Accuracy was calculated to be 89% for wetlands and 71% for uplands.

• Over 600 field sites visited

That means most of the sites we map as wetlands are indeed wetlands. Most of the sites we map as uplands are non-wetlands.

January 2002

Maps are the starting point

DCM’s wetland maps show the location and types of wetlands

What is the ecological significance of these wetlands?

How important are they?

January 2002

North Carolina Coastal Region Evaluation of Wetland

Significance(NC-CREWS)

A model that rates the A model that rates the functional significance of functional significance of

wetlandswetlands

January 2002

NC-CREWS Ratings

DCM staff developed a model that produces ratings for each wetland polygon in our GIS:

– Beneficial Functional Significance

– Substantial Functional Significance

– Exceptional Functional Significance

Wetlands can be evaluated on the basis of an overall rating or in terms of individual functions.

January 2002

NC-CREWS Primary Wetland Functions and

Subfunctions

Water Quality– Nonpoint Source

Removal– Floodwater Cleansing

Wildlife Habitat– Terrestrial Wildlife– Aquatic Life

Hydrology– Surface Runoff

Storage– Floodwater Storage– Shoreline Stabilization

Potential Risk– Wetland Extent and

Rarity– Replacement Difficulty– Land Use Characteristics

January 2002

Example: Water Quality Function

P roxim ity to Sources

P roxim ity to W ater Body

W atershed P osition

W etland Resto rationS ite T yp e

So il Characteristics

S ite Cond itio ns

N on-P o int Source Function

W ater Source & P roxim ity

D uratio n of F lo od ing

W etland Resto rationS ite T yp e

So il Characteristics

S ite Cond itio ns

W idth P erpend icu larto Stream

F lo odw ater C leansing

W ater Q uality Function

January 2002

Example: DCM GIS Wetland Type Map

DCM wetland maps show wetland location and type.

January 2002

Example: NC-CREWS Map

NC-CREWS rates a wetland’s ecological functional significance

January 2002

January 2002

Web-Based Viewing athttp://dcm2.enr.state.nc.us/

• Click on Wetlands • Click on Wetlands Data• Scroll down and click on Go to the Wetlands

Data

This application will allow you to view DCM’s wetland data online. You can begin by clicking or selecting a county or town. The wetland data will draw when you have zoomed in far enough. The map also includes major roads and water for reference.

The following slides show an example of our online data.

January 2002

January 2002

January 2002

January 2002

How to get DCM GIS Wetland Data:

• From DCM on a CD as Arc/Info Export or ShapefileWetland type, NC-CREWS, Restoration/Enhancement type data

• From CGIA- Wetland type and Restoration/Enhancement type data

• Transfer via FTP site

• Wetland Type data is in CGIA’s BasinPro