Classification of Wetlands Presentation.pptx22.pptx

Wetlands are unique ecosystems characterized by the presence of water, either permanently or seasonally, which significantly influences the soil, vegetation, and wildlife. These areas are typically found in regions where the water table is at or near the surface, or where the land is covered by shallow water. Wetlands include swamps, marshes, bogs, and fens, each with distinct characteristics and ecological functions.

Wetlands are critical for environmental health and human well-being, requiring concerted efforts to conserve and restore these valuable ecosystems.

1. CLASSIFICATION of WETLAND

2. DEFINITION “ Wetland is the low-lying ecosystem where the groundwater table is always at or near the surface. It includes areas of marsh, fen, bog, floodplain, and shallow coastal areas.”

3. WETLANDS OF BANGLADESH The total area of wetland in Bangladesh has been estimated to be 7-8 million hectares which is nearly 50% of the countries land mass.

4. Saltwater wetlands Freshwater wetlands Manmade Wetlands Classification of Wetlands

5. Saltwater wetlands : A saltwater wetlands, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides.

6. Marine: Areas with a water regime determined primarily by tides and the dominant vegetation is salt tolerant plant species. Ex- Bay, Coral reef. Some Saltwater wetlands -

7. b) Estuarine: A brackish habitat where freshwater meets the saltwater. Ex- Intertidal marshes, mangrove.

8. A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands.

9. 2. Freshwater wetlands: These freshwater wetlands occupy four landscape units- floodplains,freshwater , marshes, lakes and swamp forests. Riverine: Rivers and streams. b) Lacustrine: Haors and beels . c) Palustrine: Marshes and swamps.

10. Riverine wetlands are unique, highly productive and diverse habitats in river floodplains. They perform a wide range of functions such as flood control, water purification, carbon storage, groundwater recharge, and water storage. Some Freshwater Wetlands : a. Riverine wetland

11. Lacustrine wetlands are swamps within lakes or reservoirs with shallow depth and growth of aquatic vegetation. b. Lacustrine wetland Tanguar Haor

12. Palustrine wetlands include any inland wetland that contains ocean-derived salts in concentrations of less than 0.5 parts per thousand, and is non-tidal. The word palustrine comes from the Latin word palus or marsh. Wetlands within this category include inland marshes and swamps as well as bogs, fens, pocosins , tundra and floodplains. c. Palustrine Wetland Ratargul Swamp forest

13. 3. Manmade wetlands: A constructed wetland is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater. Ex- Ponds, irrigated land, irrigation channels, hydrodams etc.

14. The Primary Wetland Types : 1.Bog Bogs are characterized by the presence of acidic soil and water, and are dominated by mosses belonging to the genus Sphagnum. It is one of the four main types of wetlands. 2.Fen A fen is a type of peat-accumulating wetland fed by mineral-rich ground or surface water. It is one of the main types of wetlands along with marshes, swamps, and bogs.

15. 3.Swamp A swamp is a forested wetland. Swamps are considered to be transition zones because both land and water play a role in creating this environment. The water of a swamp may be fresh water, brackish water, or seawater. 4.Marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.

16. Geographical distribution: The total area under wetlands in Bangladesh has been variously estimated at seven to eight million hectares, which is about 50% of the total land surface. The areal extent of wetlands under various categories are given in the following: Open Waters Rivers 7497 Estuaries and mangrove swamps 6102 Beels and haors 1,142 Inundable floodplains 54,866 Kaptai Lake 688 Closed Waters Ponds 1,459 Baors (Oxbow Lakes) 55 Brackish-water farms 1,080 Total 72,899

17. Hakaluki Haor,Sylhet Hakaluki Haor : It is a marsh wetland ecosystem of north-eastern Bangladesh. It is one of Bangladesh's largest and one of Asia's large marsh wetland resources with a land area of 18,386 hectors. It was designated an  Ecologically Critical Area  (ECA). A total of 558 species of animals and birds have been identified here, including some very rare – already declared as threatened, vulnerable, endangered and critically endangered species.

18. Chalan Beel,Rajshahi Chalan Beel : It’s a wetland in the  Sirajganj ,  Natore  and  Pabna districts of Bangladesh. It is a large inland depression, marshy in character, with rich flora and fauna. The largest beel in Bangladesh is a depression connected by 47 rivers and other waterways. Due to silting, the bill is now divided into many small water bodies which become one in the monsoon. Padma, Jamuna , and Atria are the main sources of water.