Wetland classification

Classification of wetlands has been a problematical task, with the commonly accepted definition of what constitutes a wetland being among the major difficulties. A number of national wetland classifications exist. In the 1970s, the Ramsar Convention on Wetlands of International Importance introduced a first attempt to establish an internationally acceptable wetland classification scheme.[1]

Ramsar classification
Main article: Ramsar Classification System for Wetland Type

The Ramsar classification of wetland types is intended as a means for fast identification of the main types of wetlands for the purposes of the convention.[2]

The wetlands are classified into three major classes:

  • Marine/coastal wetlands
  • Inland wetlands
  • Human-made wetlands

These are further subdivided by the type of water: fresh / saline / brackish / alkaline; and may be further classified by the substrate type of other characteristics.

National systems of classification

Australia

Wetlands in Australia that considered to be of national importance are so classified by criteria published in association with the Directory of Important Wetlands in Australia (DIWA).[3]

The following list is that used within Australia to classify wetland by type:[4]

  • A—Marine and Coastal Zone wetlands
  1. Marine waters—permanent shallow waters less than six metres deep at low tide; includes sea bays, straits
  2. Subtidal aquatic beds; includes kelp beds, seagrasses, tropical marine meadows
  3. Coral reefs
  4. Rocky marine shores; includes rocky offshore islands, sea cliffs
  5. Sand, shingle or pebble beaches; includes sand bars, spits, sandy islets
  6. Intertidal mud, sand or salt flats
  7. Intertidal marshes; includes saltmarshes, salt meadows, saltings, raised salt marshes, tidal brackish and freshwater marshes
  8. Intertidal forested wetlands; includes mangrove swamps, nipa swamps, tidal freshwater swamp forests
  9. Brackish to saline lagoons and marshes with one or more relatively narrow connections with the sea
  10. Freshwater lagoons and marshes in the coastal zone
  11. Non-tidal freshwater forested wetlands
  • B—Inland wetlands
  1. Permanent rivers and streams; includes waterfalls
  2. Seasonal and irregular rivers and streams
  3. Inland deltas (permanent)
  4. Riverine floodplains; includes river flats, flooded river basins, seasonally flooded grassland, savanna and palm savanna
  5. Permanent freshwater lakes (> 8 ha); includes large oxbow lakes
  6. Seasonal/intermittent freshwater lakes (> 8 ha), floodplain lakes
  7. Permanent saline/brackish lakes
  8. Seasonal/intermittent saline lakes
  9. Permanent freshwater ponds (< 8 ha), marshes and swamps on inorganic soils; with emergent vegetation waterlogged for at least most of the growing season
  10. Seasonal/intermittent freshwater ponds and marshes on inorganic soils; includes sloughs, potholes; seasonally flooded meadows, sedge marshes
  11. Lakeshore mudflats in freshwater lakes and ponds
  12. Permanent saline/brackish marshes
  13. Seasonal saline marshes
  14. Shrub swamps; shrub-dominated freshwater marsh, shrub carr, alder thicket on inorganic soils
  15. Freshwater swamp forest; seasonally flooded forest, wooded swamps; on inorganic soils
  16. Peatlands; forest, shrub or open bogs
  17. Alpine and tundra wetlands; includes alpine meadows, tundra pools, temporary waters from snow melt
  18. Freshwater springs, oases and rock pools
  19. Geothermal wetlands
  20. Inland, subterranean karst wetlands
  • C—Human-made wetlands
  1. Water storage areas; reservoirs, barrages, hydro-electric dams, impoundments (generally > 8 ha)
  2. Ponds, including farm ponds, stock ponds, small tanks (generally < 8 ha)
  3. Aquaculture ponds; fish ponds, shrimp ponds
  4. Salt exploitation; salt pans, salines
  5. Excavations; gravel pits, borrow pits, mining pools
  6. Wastewater treatment; sewage farms, settling ponds, oxidation basins
  7. Irrigated land and irrigation channels; rice fields, canals, ditches
  8. Seasonally flooded arable land, farm land

United States

Wetlands of the United States are classified according to the U.S. Fish and Wildlife Service's National Wetlands Inventory (NWI).[5]

In the US, the best known classification systems are the Cowardin classification system and the hydrogeomorphic (HGM) classification system.

See also

References
  1. Scott, D. A.; Jones, T. A. (1995). "Classification and inventory of wetlands: A global overview". Vegetatio. 118 (1–2): 3–16. doi:10.1007/BF00045186. S2CID 24404467.
  2. "Ramsar Classification System for Wetland Type"
  3. "Directory of Important Wetlands in Australia". Commonwealth of Australia. Retrieved 7 October 2015.
  4. "A Directory of Important Wetlands in Australia: Third edition, Chapter 2: Wetland classification system, Criteria for inclusion and Data presentation". Australian Department of the Environment. 2001. Retrieved 30 March 2021.
  5. "Wetlands Digital Data". Archived from the original on 2008-05-14. Retrieved 2009-02-10.
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