What are Wetlands?

In general, a wetland is an area of land whose soil is saturated with moisture either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water.

Wetlands are ecotone of land and water. They vary in both of their functions and forms.

In terms of functions, there are many wetlands that storage or purify water. In addition, a wetland can serve as a habitat for living creatures, especially aquatic creatures and their predators: water birds. These water and biotic resources provided by wetlands are also vital to human beings.

In terms of forms, wetlands include low swamps, marshes, high and low moors, moss bogs, seasonal and intermittent pools etc. They also include saline wetlands on seacoast or estuary, mangrove marshes, freshwater wetlands on prairie, floodplain lakes and coastal lagoons.

Definition of Wetlands

The Ramsar Convention on Wetlands defines wetlands as follows:

Article 1. For the purpose of this Convention wetlands are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres. (entire text available at the Ramsar Secretariat website)

“Ramsar Classification System for Wetland Type”

“Ramsar Classification System for Wetland Type” is the code approved by the Ramsar Contracting Parties, which are used upon designation of Ramsar Sites. It classifies wetlands into 42 types:

Ramsar Classification System for Wetland Type 

Marine/Coastal Wetlands
1 A Permanent shallow marine waters
2 B Marine subtidal aquatic beds
3 C Coral reefs
4 D Rocky marine shores
5 E Sand, shingle or pebble shores
6 F Estuarine waters
7 G Intertidal mud, sand or salt flats
8 H Intertidal marshes
9 I Intertidal forested wetlands
10 J Coastal brackish/saline lagoons
11 K Coastal freshwater lagoons
12 Zk(a) Karst and other subterranean hydrological systems, marine/ coastal
Inland Wetlands
13 L Permanent inland deltas
14 M Permanent rivers/streams/creeks
15 N Seasonal/intermittent/irregular rivers/streams/creeks
16 O Permanent freshwater lakes
17 P Seasonal/intermittent freshwater lakes
18 Q Permanent saline/brackish/alkaline lakes
19 R Seasonal/intermittent saline/brackish/alkaline lakes and flats
20 Sp Permanent saline/brackish/alkaline marshes/pools
21 Ss Seasonal/intermittent saline/brackish/alkaline marshes/pools
22 Tp Permanent freshwater marshes/pools
23 Ts Seasonal/intermittent freshwater marshes/pools on inorganic soils
24 U Non-forested peatlands
25 Va Alpine wetlands
26 Vt Tundra wetlands
27 W Shrub-dominated wetlands
28 Xf Freshwater, tree-dominated wetlands
29 Xp Forested peatlands
30 Y Freshwater springs; oases
31 Zg Geothermal wetlands
32 Zk(b) Karst and other subterranean hydrological systems, inland

Human-made wetlands
33 1 Aquaculture ponds
34 2 Ponds
35 3 Irrigated land
36 4 Seasonally flooded agricultural land
37 5 Salt exploitation sites
38 6 Water storage areas
39 7 Excavations
40 8 Wastewater treatment areas
41 9 Canals and drainage channels, ditches
42 Zk(c) Karst and other subterranean hydrological systems, human-made

(original detailed classification in Resolution Ⅷ.13 available at the Ramsar Secretariat website)