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The coastal zone is the interface where the land meets the ocean or sea, encompassing shoreline environments as well as adjacent coastal water. Its components include river deltas, coastal plains, wetlands, beaches and dunes, reefs, mangrove forests, lagoons, and other coastal features. It is a geomorphologic area either side of the seashore in which the interaction between the marine and land parts occurs in the form of complex ecological and resource systems made up of biotic and a biotic components coexisting and interacting with human communities and relevant socio-economic activities. It has no definite boundary, it varies from one coastal nation to another nation as they defined it. In Sri Lanka, Coastal Zone is defined as the area lying within a limit of 300 m landward of the Mean High Water Line (MHWL) and a limit of 2 km seaward of the Mean Low Water Line (MLWL); in the case of estuaries, streams and river outfalls, lagoons, or any other body of water connected to the sea either permanently or periodically, the landward boundary extends up to a limit of 2 km measured perpendicular to the straight base line drawn between the natural entrance points thereof and includes the waters of such rivers, streams and lagoons or any other body of water so connected to the sea.
Coastal zone has several definitions. Ketchum has given a definition in (1972) as “The band of dry land and adjacent ocean space in which terrestrial processes and land uses directly affect oceanic processes and uses and vice versa.” However this definition also has some problem since it has not considered the all coastal ecosystems. Coastal zone is commonly referred to as the interface or transition space between two environmental domains, the land and the sea. Coastal area consists only 8% of the world surface area but it provides 25% of the global productivity. In addition to the above 70% of the world’s population is living within the coastal areas. The coastal area in the world also consists of very valuable resources such as fish, mineral corals, mangroves, lagoon and estuaries, gas and mineral (ICRMP). About 90% world’s fish harvest comes from the coastal area. Therefore coastal area is very important to the world economy and the population. However coastal zone or coast is not a well-defined resource. Coast is physically dynamic edges between land and sea and comprised of numerous physiographic forms: dunes, deltas, beaches, wetland etc. it also has a wide range of ecosystems such as coral reefs, mangroves, sand dunes, sea grass beds, estuaries and lagoons. The coastal area serves as habitats for countless flora and fauna. More importantly coastal areas are the locus of an incredibly diverse range of human uses and activities. |
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