Wetlands are land areas which either permanently or seasonally saturated with water. According to Ramsar Convention on Wetlands; wetlands are defined 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 areas of marine water the depth of which at low tide does not exceed six meters”. Among many other ecosystems, wetlands are the most productive ecosystems in the world. Since many type of plants and animals dependent on this ecosystem, the biodiversity in wetlands is extremely high. There are many types of wetlands can be found in our environment and according to Ramsar Convention there are five wetland types have been generally recognized.
1) Marine (coastal wetlands including coastal lagoons, rocky shores, and coral reefs)
2) Estuarine (including deltas, tidal marshes, and mangrove swamps)
3) Lacustrine (wetlands associated with lakes)
4) Riverine (wetlands along rivers and streams)
5) Palustrine (meaning “marshy” – marshes, swamps and bogs)
Wetland system in the Sri Lanka provides many values for the environment and plays a significant role in the economy of the country. These economic and social benefits include, preventing flood in domestic and commercial areas, contribute to the fisheries and agriculture, provide sources for raw materials for different industries, and serves as significant source of foreign income through eco-tourism. Many wetlands in the country, such as Bundala and Kalametiya, serve as refugees for migrating birds, hence they have received a considerable amount of attention, especially from bird-watchers, and play an important role in the tourism industry. Sri Lanka presently has 6 sites designated as Wetlands of International Importance.
A wetland which is located within and around cities (urban areas ) are known as urban wetlands. Since these are the only natural ecosystem remaining in many urban areas, they play a vital role in the cities and life of city dwellers. Flood controlling, water purification, city cooling, serving as wildlife habitats in urban areas, giving aesthetic value are some of the values provide by urban wetlands. Main Urban wetlands in Sri Lanka are Muthurajawela, Colombo Flood Detention Area, Bellanwila Attidiya marsh, Bolgoda lake and marshes ,Negamboo lagoon , Kokgala Estuary and mangroves , Jaffna lagoon.
