The Space Applications Centre, Ahmedabad, of ISRO has come out with a detailed scientific investigation of the entire coastal zone in India. BIJU GOVIND looks at the Kerala angle.
The Kerala coast is world famous. If, in the present world, tourists are its goodwill ambassadors, in the centuries gone by, traders from distant lands used to ply its fame far and wide, charting the oceans to get a piece of the richness of the land.
The sandy shores on a straight line from Manjeswaram in the north to Pozhiyur down south, traversing 576 km, has an inextricable link with the life, legend and culture of the State.
Helping to know them better is the Space Applications Centre in Ahmedabad of the Indian Space Research Organisation as it has come out with a detailed scientific investigation of the entire coastal zone in India.
Its voluminous Coastal Zones of India says that the Kerala coast is famous for its beautiful beaches, estuaries and lagoons. The more or less linear coastline is at some places offset by promontories. A characteristic feature of its is the high population density, 2,362 persons per sq.km, resulting in a more or less urbanised coastal zone.
Well-developed sandy beaches can be found in Chittari, Kappad, Ponnani, Kozhikode, Kochi, Alappuzha and Kovalam. These beaches have sands of different fractions, along with broken molluscan shells. Crescent-shaped pocket beaches are found at Ezhimala, Dharmadom, Thalassery, Kadalur and Elathur. Spits are seen in the estuaries of Vembanad, Asthamudi, Beypore and Veli. At some places, during the lean season, small estuaries get blocked by the growth of spits.
Cliff and rocky coasts are found at many places in the State. The rocky shores are made up of laterites or Precambrian crystalline materials such as Khondalites or Charnockites. Some of the prominent rocky coasts are near Bekal and at Ezhimala, Azhikode and Kadalur in the north and at Vizhinjam, Varkala and Tangasseri in the south.
The mangrove vegetation in the coastal area of Kerala is sparse and thin. The coast has a number of islets or islands. Most of them are populated. Locally, the islands are called Thuruths. Manmade islands are common. The Vembanad, the Asthamudi and the Kavvayi estuaries show more islands. The islands in the Vembanad estuary in central Kerala are larger than those in the Kavvayi estuary in Payyannur. The major islands are Willingdon, Kumbalam, Nettur, Madavana, Cheppanam and Perumbalam. Dharmadom, a large island with mangroves, is in northern Kerala.
The shore has many wetlands, including estuaries and backwaters. However, population pressure and subsequent infrastructure development have prompted land reclamation on a large scale in coastal areas, a main reason attributed for the dwindling of this natural resource.
Agriculture, extensive aquaculture practices and in recent years tourism have contributed to its decline. Major mangrove-harbouring areas in the State are in Valapattanam, Kunhimangalam, Kasargod-Nileswaram, Kavvayi and Puthuvypeen. Mangrove areas in the State are largely under private ownership. Some plantations of mangrove have been raised, the report says.
Rapid urbanisation, tourism development, discharge of waste effluents, municipal sewerage and overexploitation have affected the 7,500-km coastal zone in India. Ever since the Union Ministry of Environment and Forests issued the Coastal Regulation Zone (CRZ) notification in 1991, the activities in the coastal zones are being monitored and regulated.
Now the coastal zones are regulated by a CRZ notification in 2011.
Previously, the Space Applications Centre, ISRO, in Ahmadabad mapped the entire coastal zone in the country using satellite data. These have been extensively used in implementing the CRZ in the past 20 years. Recently, it came out with the detailed scientific investigation.
The study includes inventory of coastal land use, along with demarcation of the high-tide line, low-tide line and ecologically sensitive area, mapping and monitoring of coral reefs and mangroves, impact of sea-level rise on the Indian coastal environment and development of a coastal zone information system.
Rangnath R. Navalgund, Director, Space Application Centre, says coastal zones are highly dynamic areas of interaction between terrestrial and marine processes. Although, coastal zones constitute about 10 per cent of the land area, these are densely populated, sustaining as much as 60 per cent of the world’s population. The processes of erosion and sedimentation, periodic storms and cyclones and sea-level changes continuously modify shoreline.
He says the entire stretch of the coastal line of India assumes its importance because of high productivity of its ecosystems, exploitation of natural resources, industrial and port development, discharge of waste effluents and increased tourism activities.
The Coastal Zone Studies’ project addressed the various aspects of the Indian coastal zone, including preparation of baseline information on the CRZ, inventory of coastal land use, including ecologically sensitive areas of the entire Indian coast, Mr. Navalgund says.
Different countries use different distance criteria for defining the coastal zone. In India, 500 metres from the high-tide line (landward) is taken for demarcating the coastal zone.
Because of the economic benefits that accrue from access to ocean navigation, coastal fisheries, tourism, recreation and industrialisation, human settlements are often more concentrated in the coastal zone than elsewhere.
Kerala coast is famous for its beautiful beaches, estuaries and lagoons.
High population density of 2,362 per sq.km
Mangrove vegetation sparse and thin
Population pressure prompts land reclamation