Maarg Manthan · Topic 9.11

Wetlands: Definition, Types and Importance

Environment & Ecology › Coastal and Wetland Ecosystems · Topic 9.11

Wetlands are areas where water covers the soil, or is present near the surface, for all or part of the year, so that the land and its plants and animals are shaped by water. The Ramsar Convention defines wetlands broadly as 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 marine water whose depth at low tide does not exceed six metres. The Ramsar system groups wetlands into marine and coastal (such as estuaries, mangroves, coral reefs, seagrass beds and lagoons), inland (such as lakes, rivers, floodplains, marshes, swamps, peatlands and oxbow lakes) and human-made (such as reservoirs, tanks, ponds, paddy fields, canals and salt pans). Wetlands recharge groundwater, store floodwater, purify water, store carbon, support rich biodiversity and sustain livelihoods. India's Wetlands (Conservation and Management) Rules, 2017 regulate them, and World Wetlands Day is on 2 February.

5 min read · UPSC Prelims · Environment & Ecology · Coastal and Wetland Ecosystems

At a Glance

Definition Ramsar broad definition
Groups Marine, inland, human-made
Marine depth limit 6 m at low tide
Indian rules Wetlands Rules, 2017
Day 2 February
Exam link UPSC Prelims, Environment & Ecology: Coastal and Wetland Ecosystems

Where Does It Fit?

This topic opens the wetland section of the macro on coastal and wetland ecosystems. It broadens the view from estuaries, mangroves and corals to all kinds of water-dominated habitats, and leads to Indian wetlands and the Ramsar Convention. Previous topic: Threats to and Conservation of Coral Reefs. Next topic: Wetlands in India and Threats to Wetland Ecosystems.

What Are the Main Types of Wetlands?

Group and type	Features and examples
Marine and coastal	Coral reefs, seagrass beds, mangroves, estuaries, lagoons, salt marshes and rocky shores. Examples: Gulf of Mannar, Chilika
Inland: lakes and ponds	Standing fresh or saline water, such as Wular, Loktak and Sambhar
Inland: rivers and floodplains	Flowing waters and the land flooded in monsoon, such as Brahmaputra floodplains
Marsh	Wetland dominated by soft-stemmed plants like reeds and sedges, with mineral soil
Swamp	Wetland dominated by trees and shrubs, such as forested swamps
Bog and fen	Peat-forming wetlands; bogs get water from rain and fens from groundwater
Human-made	Reservoirs, village tanks, ponds, paddy fields, canals, aquaculture ponds and salt pans

Why Are Wetlands Important?

Water supply: recharge groundwater and keep streams flowing in dry months
Flood control: store and slowly release flood water
Water purification: plants and soil trap sediment, nutrients and pollutants
Carbon storage: peatlands and mangroves hold large carbon stocks
Biodiversity: habitat for fish, amphibians, waterbirds and many plants
Food and livelihoods: fish, rice, reeds, medicinal plants and tourism
Climate regulation: moderate local climate and buffer coasts from storms
Culture and recreation: sacred lakes, festivals, boating and bird watching

What Else Should You Remember?

Ramsar definition: deliberately wide, so that it covers coastal and human-made areas as well as natural inland ones
Six metre rule: marine waters up to six metres deep at low tide are counted
Peatland: wetland with a thick layer of partly decayed plant matter, a huge carbon store
Fen and bog: fens are fed by groundwater and richer in minerals; bogs by rain and more acidic
Marsh and swamp: marsh has soft plants like reeds, swamp has woody plants
Oxbow lake: a crescent lake formed when a river meander is cut off, common on floodplains
Floodplain: land next to a river that floods in the high-flow season
Playa: a dry lake bed that fills occasionally, found in desert areas
Salt pans: shallow areas used for sea salt making, which are also bird habitats
Tanks: village reservoirs, especially in southern India, that store rain water
Paddy fields: human-made wetlands that also support fish, frogs and birds
Flood pulse: the seasonal rise and fall of water that drives wetland productivity
Hydrophytes: plants adapted to water, such as lotus, water lily and reeds
Hydric soil: soil formed under conditions of flooding long enough to lack oxygen
Kidneys of the landscape: a common phrase for wetlands as natural water filters
Global area: wetlands cover only a small share of the land but hold a very large part of freshwater species
Loss rate: global assessments show that a large part of wetlands has been lost since 1700, and losses continue
Wetlands Rules, 2017: replaced the 2010 rules and shifted regulation to state wetland authorities
State Wetlands Authority: each state sets up one to notify and manage wetlands
Wise use: Ramsar term for maintaining wetlands’ ecological character while allowing sustainable use
World Wetlands Day: 2 February, marking the signing of the Ramsar Convention in 1971
Link to previous: see Threats to and Conservation of Coral Reefs
Link to next: see Wetlands in India and Threats to Wetland Ecosystems
Link to rules: see Wetland (Conservation and Management) Rules, 2010
Caution: definitions differ across laws; the Indian rules exclude some water bodies, so read the latest text
Exam hint: learn the three Ramsar groups, with an example for each, and the marsh, swamp, bog, fen differences

Why Does It Matter for the Exam?

Definition source: Ramsar
Groups: Marine, inland, human-made
Rules: Wetlands Rules, 2017
Current affairs link: Ramsar site additions
Common errors: treating only lakes as wetlands or mixing bog and fen

As an analytical point, wetlands are a bundle of free services, such as flood storage, filtration and carbon storage, which cities and farms often fail to count. Valuing them in rupees helps weigh them against land conversion.

Why Is This Topic Important?

Water Recharge
Hazard Flood buffer
Climate Carbon store

What Came Next?

The next topic covers wetlands in India and the threats to wetland ecosystems. Next topic: Wetlands in India and Threats to Wetland Ecosystems.

Key People and Terms

Wetland Water-dominated habitat
Peatland Peat-rich wetland
Marsh Soft plant wetland
Swamp Tree wetland
Oxbow lake Cut-off river bend
Wise use Sustainable wetland use

Exam Corner

Points to Remember

Ramsar groups: three.
Marine depth limit: 6 m.
Rules: 2017.
Day: 2 February.
Wetlands are natural filters.

Do Not Confuse With

Marsh and swamp Soft plants versus woody plants
Bog and fen Rain-fed versus groundwater-fed
Wetland and water body Broad Ramsar term versus any pond or lake

Memory Hook

Three groups, six metres, marsh soft, swamp wood, day is two Feb.

Mains Angle

Questions ask for types and functions. These points help.

Types Three groups
Value Services
Rules 2017

A Question You May Face

An original practice question, not a past paper question.

“What are wetlands? Classify them and discuss their ecological and economic importance.”

How to Answer

Define Ramsar.
Types Three.
Value Services.
Way Wise use.

GS Relevance

Prelims: definition, types, functions, Ramsar. GS Paper 3: conservation of wetlands and water ecosystems.

Frequently Asked Questions

What is a wetland?

A wetland is an area where water covers the soil or stays near the surface for all or part of the year, so that its soil, plants and animals are shaped by water. The Ramsar Convention includes marshes, lakes, rivers, floodplains, estuaries, mangroves, coral reefs, and human-made sites such as reservoirs and paddy fields.

What are the main types of wetlands?

Wetlands are grouped into marine and coastal wetlands such as lagoons, mangroves and coral reefs, inland wetlands such as lakes, rivers, floodplains, marshes and swamps, and human-made wetlands such as reservoirs, tanks, ponds, canals and salt pans. Peat-forming bogs and fens are special inland types.

What is the difference between a marsh and a swamp?

A marsh is a wetland where soft-stemmed plants such as reeds, sedges and grasses dominate, usually on mineral soil. A swamp is a wetland dominated by trees and shrubs, such as forested swamps in river deltas or floodplains. Both are flooded for long periods but support different plants and animals.

Why are wetlands called the kidneys of the landscape?

Wetland plants, soils and microbes trap sediments and absorb or break down nutrients and many pollutants as water passes through, much as kidneys filter blood. This natural cleaning improves water quality, protects rivers and lakes downstream and reduces the cost of treating water.

Which Indian rules regulate wetlands?

The Wetlands (Conservation and Management) Rules, 2017, issued under the Environment (Protection) Act, 1986, regulate wetlands in India. They replaced the 2010 rules, create State Wetlands Authorities to identify and manage wetlands and restrict activities such as reclamation, solid waste dumping and industrial effluent discharge in them.

PYQ Practice — Statement Analysis

1 Ramsar groups wetlands into marine, inland and human-made types.

True

Three broad groups.

2 A swamp is dominated by soft reeds and sedges.

False

That describes a marsh.

3 Paddy fields can be human-made wetlands.