400 likes | 745 Views
Wetland Types, Functions, and DCM’s GIS Wetland Data North Carolina Department of Environment and Natural Resources Division of Coastal Management. DCM GIS Wetland Data:. Wetland Type Data Wetland Functional Significance Data Potential Wetland Restoration and Enhancement Site Data
E N D
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
Topics • Wetlands • Wetland Functions • Wetland Types • GIS Wetland Data • NC-CREWS Data • Getting DCM’s Data January 2002
Wetlands Wetlands are areas that are periodically or permanently inundated by surface or ground water and support vegetation adapted for life in saturated soil. Wetlands include swamps, marshes, bogs and similar areas. January 2002
What do wetlands do? Wetland Functions Habitat nesting, spawning, rearing and resting sites for aquatic and land species, food chain production Hydrology protection of other areas from wave action and erosion, storage areas for storm water and flood water, ground and surface water aquifer recharge Water water quality protection, water filtration and Quality purification, treatment of nonpoint source runoff January 2002
Why are wetlands important? Wetland Values • maintain biodiversity • provide habitat for animals • maintain water quality • support commercial fishing, forestry • reduce flood damage • hiking, fishing, hunting, • bird watching, boating • aesthetic value Did you know? Nationwide, an estimated 50 million people spend approximately $10 billion annually observing and photographing wetland-dependent birds. January 2002
There are many different kinds of wetlands. People place different values on them based on the functions they perform. January 2002
Where are wetlands located? • Wetlands are located throughout NC • There are two kinds of maps in NC that show the locations and types of wetlands: • National Wetland Inventory (NWI) Maps • DCM 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 2002
DCM’s maps show 13 wetland types January 2002 Example: DCM Wetland Type Map
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
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
Wet Pine Flat Hard Wood 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 functional significance of wetlands 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-CREWSPrimary 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 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
Web-Based Viewing at http://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
How to get DCM GIS Wetland Data: • From DCM on a CD as Arc/Info Export or Shapefile Wetland 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 January 2002