Classification of wetlands has been a problematical task, with the commonly accepted definition of what constitutes a

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

being among the major difficulties. A number of national wetland classifications exist. In the 1970s, the

Ramsar Convention on Wetlands of International Importance The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar sites (wetlands). It is also known as the Convention on Wetlands. It i ...

introduced a first attempt to establish an internationally acceptable wetland classification scheme.

Ramsar classification

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. 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 Fresh may refer to: Arts, entertainment, and media Films and television * ''Fresh'' (1994 film), a crime film * ''Fresh'' (2009 film), a documentary film on sustainable agriculture * ''Fresh'' (2022 film), a thriller film *''Fresh with the Aust ...

saline Saline may refer to: Salt-related * Saline (medicine), a liquid with salt content to match the human body * Saline water, non-medicinal salt water * Saline, a historical term (especially American) for a salt works or saltern Places United States ...

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

; and may be further classified by the substrate type of other characteristics.

National systems of classification

Australia

Wetlands in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

that considered to be of national importance are so classified by criteria published in association with the

Directory of Important Wetlands in Australia A Directory of Important Wetlands in Australia (DIWA) is a list of wetlands of national importance to Australia published by the Department of Climate Change, Energy, the Environment and Water. Intended to augment the list of wetlands of internatio ...

(DIWA). The following list is that used within

to classify wetland by type: * A—Marine and Coastal Zone wetlands # Marine waters—permanent shallow waters less than six metres deep at low tide; includes sea bays, straits # Subtidal aquatic beds; includes kelp beds, seagrasses, tropical marine meadows # Coral reefs # Rocky marine shores; includes rocky offshore islands, sea cliffs # Sand, shingle or pebble beaches; includes sand bars, spits, sandy islets # Intertidal mud, sand or salt flats # Intertidal marshes; includes saltmarshes, salt meadows, saltings, raised salt marshes, tidal brackish and freshwater marshes # Intertidal forested wetlands; includes mangrove swamps, nipa swamps, tidal freshwater swamp forests # Brackish to saline lagoons and marshes with one or more relatively narrow connections with the sea # Freshwater lagoons and marshes in the coastal zone # Non-tidal freshwater forested wetlands * B—Inland wetlands # Permanent rivers and streams; includes waterfalls # Seasonal and irregular rivers and streams # Inland deltas (permanent) # Riverine floodplains; includes river flats, flooded river basins, seasonally flooded grassland, savanna and palm savanna # Permanent freshwater lakes (> 8 ha); includes large oxbow lakes # Seasonal/intermittent freshwater lakes (> 8 ha), floodplain lakes # Permanent saline/brackish lakes # Seasonal/intermittent saline lakes # Permanent freshwater ponds (< 8 ha), marshes and swamps on inorganic soils; with emergent vegetation waterlogged for at least most of the growing season # Seasonal/intermittent freshwater ponds and marshes on inorganic soils; includes

sloughs A slough ( or ) is a wetland, usually a swamp or shallow lake, often a Backwater (river), backwater to a larger body of water. Water tends to be Water stagnation, stagnant or may flow slowly on a seasonal basis. In North America, "slough" may re ...

, potholes; seasonally flooded meadows, sedge marshes # Lakeshore mudflats in freshwater lakes and ponds # Permanent saline/brackish marshes # Seasonal saline marshes # Shrub swamps; shrub-dominated freshwater marsh, shrub carr, alder thicket on inorganic soils # Freshwater swamp forest; seasonally flooded forest, wooded swamps; on inorganic soils # Peatlands; forest, shrub or open bogs # Alpine and tundra wetlands; includes alpine meadows, tundra pools, temporary waters from snow melt # Freshwater springs, oases and rock pools # Geothermal wetlands # Inland, subterranean karst wetlands * C—Human-made wetlands # Water storage areas; reservoirs, barrages, hydro-electric dams, impoundments (generally > 8 ha) # Ponds, including farm ponds, stock ponds, small tanks (generally < 8 ha) # Aquaculture ponds; fish ponds, shrimp ponds # Salt exploitation; salt pans, salines # Excavations; gravel pits, borrow pits, mining pools # Wastewater treatment; sewage farms, settling ponds, oxidation basins # Irrigated land and irrigation channels; rice fields, canals, ditches # Seasonally flooded arable land, farm land

United States

Wetlands of the United States Wetlands of the United States are defined by the United States Army Corps of Engineers and the United States Environmental Protection Agency as "those areas that are inundated or saturated by surface or ground water at a frequency and duration su ...

are classified according to the U.S. Fish and Wildlife Service's

National Wetlands Inventory The National Wetlands Inventory (NWI) was established by the United States Fish and Wildlife Service (FWS) to conduct a nationwide inventory of U.S. wetlands to provide biologists and others with information on the distribution and type of wetlands ...

(NWI). In the US, the best known classification systems are the

Cowardin classification system The Cowardin classification system is a system for classifying wetlands, devised by Lewis M. Cowardin ''et al.'' in 1979 for the United States Fish and Wildlife Service. The system includes five main types of wetlands: # Marine wetlands, which ar ...

and the hydrogeomorphic (HGM) classification system.

References

{{aquatic ecosystem topics Wetlands Geographic classifications

Ramsar classification

National systems of classification

Australia

United States

See also

References