The vanishing shore
The country’s coastline is under threat from climate change and human activities. Experts are converging to prepare maps to pin down the changes and need for future plan in this sector. Nasreen Khan reports
Cyclone Thane hit the southern shores of the country recently leaving major devastations in its wake. Memories of tsunami, though it happened more than five years ago, recurred all over again. Another Aila, the cyclone that had devastated Bengal’s coastline in 2009, is not a remote possibility either. Nature’s fury is way beyond human control and the ensuing destructions. Now that 2012 is here some even predict the end of the world citing an old Mayan calendar. The disaster movie 2012 from the Hollywood mill has generated its own fear psyche. To add to the fear of doomsday is the fact that the number of people exposed to natural disasters is expected to more than double by 2050. Well, that gives us a few more years. But the sad truth is that millions of victims are likely to be from India. The culprit, says the World Bank, is rapid urbanisation and the extreme weather stemming from climate change.
With such nature- induced holocaust staring us in the eye, the shoreline mapping project along the coast of India by the National Centre for Sustainable Coastal Management (NCSCM), Chennai, is a welcome move. The Sundarbans in West Bengal has been identified globally as a critically affected area.
Both erosion (leading to land being swallowed up by the sea) and accretion (deposit of sediments that makes ports like Haldia useless) are natural processes but human activity is interfering with nature’s trail too. “The entire Medinipur stretch of the coast, west of river Hooghly is predominantly under accretion from Digha to Mandermoni. While the lower and middle sectors of Sundarban estuarine system is under intense erosion, the head-ward portion of the same shows accretion. This is the typical response of any micro tidal estuary against sea level rise,” says Kakoli Sen Sarma, geologist cum remote sensing specialist from the Integrated Coastal Zone Management (ICZM) project at the Institute of Environmental Studies and Wetland Management (IESWM), Kolkata. Sen Sarma has recently concluded a study of the dynamic nature of the Sundarban estuary on the West Bengal coast.
“The present shoreline change analysis by NCSCM shows that nearly 67.9% of the West Bengal coast is under erosion. This clearly shows that we cannot have ports and other mega structures along eroding coasts. This has a negative impact on our economy. Hence we urgently need shoreline change mapping. It is a mechanism to understand why such changes are taking place and what we can do to change the same,” says Debal Ray, chief environment officer, Government of West Bengal.
“This shoreline change assessment for the coast of India represents long-term shoreline change for a period of 38 years from 1972-2010,” shares R Ramesh, director, NCSCM.
Shoreline change evaluations are based on comparing four to five historical shorelines, archived from satellite imageries for the above time period, with recent shoreline derived from LISS III images and limited field surveys. “The primary goal of this study is to develop standardised methods for mapping and analysing shoreline movement so that internally consistent updates can periodically be made to record shoreline erosion and accretion. The by product of this mapping will be to help formulate policies and plans to safeguard the future.
“Extreme cases of intensive pressure of human population on coastal ecosystems are seen in India. Over 25% of India’s population will live in coastal areas during this century. Many large cities and urban habitations are also near the seacoast,” noted M S Swaminathan in the review of the Coastal Regulation Zone Notification 1991.
It is a common knowledge that human activity is both directly as well as indirectly responsible for the process of erosion and accretion along the coasts. There is excessive pressure on the mainland pushing the population to the next habitable area. Besides fishing, other new industries along the coast (power sector and tourism in particular) are adding to the load of the already vulnerable coastal zones in the country. Mapping is essential to know the coastal resources as well as to protect them. The scientific community is unanimous in its opinion that for the first time, this study will be able to map the undeniable climatic signature along the coast of India.
The National Atlas and Thematic Mapping Organisation too is preparing to map the different kinds of human activities (land use) in the coastal mega cities of India. “We have a Golden Map project on the anvil which will help study the impact of human activity on the coastal zones. We will make use of the shoreline mapping,” informs Sandhya Bhaduri, from National Atlas and Thematic Mapping Organisation.
However, shoreline mapping is not a new development. It started way back in the 1800s when shipping between the states took place along the coast because land transportation was not well developed. Foreign trade, correspondence and diplomatic forays, etc. were all accomplished through the sea route. Commercial fishing was, and still is, a large industry. This reliance on ships and the sea sparked a need for a comprehensive effort to survey the coastal route and publish the findings. Along with it there was felt need for mapping the land, including the shoreline, natural and cultural features, and elevations above the sea for a better understanding of the coast.
In India, such an intensive and scientifically accurate study regarding the impact of human activity and erosion-accretion of the coasts is being done for the first time. Interestingly the remote sensing based mapping of the Coastal Regulation Zone (CRZ) violations along the West Bengal coast has already been done. Field surveys are going on to verify the same before the findings are submitted to the authorities.
Already reports of most violated blocks namely, Namkhana and Gosaba, in the Sundarbans have been submitted to the environment department. Sources claim that even government organisations have been enlisted in the long list of CRZ violators. It is to be noted that such violations directly affect the shores adversely. Those in the administration insist that West Bengal is serious about CRZ. It remains to be seen what use the policy makers make of such studies.
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