Impacts of coastal erosion on the fishing communities : a case study of Pondicherry

Abstract

The drift along Pondicherry and the neighboring zones of the Villupuram locality has been encountering serious Erosional problem for as far back as 25 years. Regular interferences of littoral float by the harbor at Ariyankuppam town, Pondicherry built in 1990 and the consequent development of the shoreline safeguard structures, for example, seawalls and crotches brought on erosion in this area. Pondicherry and Tamil Nadu governments made a few endeavors to ensure the drift under risk utilizing alternatives like seawalls and crotches. Despite the fact that these protection measures have offered some help to the drift under danger, contiguous parts of drift zones are dissolving making it very unstable and are continually under risk. There is a requirement for an all-round characterized arrangement for that looks to treat the shoreline and the issue of disintegration in a more incorporated, practical and vital way. This can be accomplished by a Shoreline Management Plan (SMP), which considers the issues at a sensible scale and concentrates on reestablishing the regular sandy shorelines. Arrangement producers, designers and partners look for a long haul answer for reestablish the sandy shorelines of this whole influenced locale. The fundamental inquiries which should be addressed and comprehended before undertaking any such shoreline management plan are: To Identify Present status of shoreline (geomorphic setting and useful execution of officially actualized security measures) and identify the Coastal procedures along this drift in connection to proposed seaside reclamation plans and also know the Priorities of the stakeholders and the policy and plan makers and the Requirements of partners along with the Economical, natural and social supportability of proposed reclamation measures Considering the over, the general goal of the seaside reclamation venture ought to be to address the beach front rebuilding needs through the execution of monetarily feasible reclamation works utilizing natural and socially suitable arrangements. This report portrays the present status of the drift and the execution of existing beach front insurance plans. The information on ocean bathymetry, arrive geology, hydrodynamics (tides, waves, streams and silt qualities) and shoreline changes was gathered for breaking down the waterfront forms. A joint meeting with Tamil Nadu and Pondicherry governments is required to draw procedures for waterfront reclamation measures where different specialized choices can be investigated in connection to the needs of the administration keeping in view that the arrangement embraced ought to be supportable, long haul and changeless without influencing the coastline found further north. The investigation of long haul shoreline change information show that the normal rate of shoreline subsidence and movement over a time of 30 years is all together of 4 m/yr and 5 m/yr individually. Nonetheless, confined shoreline change rates, subsidence particularly, of 50 m in a season were watched. In any case, the rate of shoreline change and additionally disintegration is subject to slope of residue transport along the drift, which is reliant on arrangement of the drift, close shore current and accessibility of the dregs. The 18 km length of coastline of Pondicherry was partitioned into four zones for investigation. The primary (Zone A) covering a length of 3.5 km speaks to the zone of direct impact of the Pondicherry harbor. The sand has amassed up to the tip of the south sea wall with most extreme gradual addition of 180 m and the residue began bypassing toward the north. The northern side of the harbor is ensured by a seawall and dregs affidavit is seen amid the NE rainstorm because of the southerly float. The most extreme erosion is around 45 m at separation of 600 m from North Sea wall from 1991 to 2000. The second (Zone B-4 km), which is a piece of Pondicherry township is ensured by a seawall. Scouring at the foot of the seawall is seen amid dynamic rainstorm. The third (Zone C-2.5 km) is ensured by a progression of disconnected crotches. These crotches were developed amid 2005-2007 and gradual addition to a degree of 120 m is seen at northern longest crotch situated at Thanthirayankuppam. The growth at all crotch compartments demonstrate accessibility of silt along the Pondicherry drift amid both storms. The CWPRS (1978) has announced that the net float was evaluated to be around 500,000 cu.m. at the season of plan of Pondicherry Harbor however the present evaluated rate of net float by us would be in the request of 2,00,000 – 2,80,000 cu m, which should be affirmed by point by point shoreline checking. The drift north of longest crotch at Chinnamudalaiyar Chavadi town has encountered expanded erosion and shoreline retreat amid 2008 to a degree of 70 m. South of this drift recaptured some lost material amid 2016 because of southerly float and bypassing of residue from the crotch with a net reduction of 80 m. The Zone D with a length of 8 km is not ensured by real plan and most extreme disintegration watched 1991-2016 is around 50m. An ocean mass of length 165 m was built at town Chinnakalapettai to shield the drift from disintegration. The accompanying are significant perceptions for touching base at waterfront rebuilding systems for both the Pondicherry and adjoining Tamil Nadu drift. Pondicherry has been known as a wonderful shoreline town. The shorelines here, especially along the well-known shoreline street were utilized for a wide range of exercises by a huge cross-area of individuals. Youngsters pursued crabs and searched for fascinating shells. The well-known Masi Magam celebration of Pondicherry depended on the huge shoreline where the chariots of the considerable number of divine beings from every one of the sanctuaries close and far would come. With the shoreline practically gone and the rough ocean divider, all these little regular joys of every single occupant of Pondicherry and each one of the individuals who throng to its shores, have been grabbed away. The essential goal of shore reclamation ventures direct the long haul normal disintegration rate and shoreline change from man-made causes, which can be accomplished just if the characteristic flow of the drift is surely knew. The medium term examination of shoreline change information from 1991 - 2016, demonstrate that this locale needs quick consideration. Protection plans till date have been executed in seclusion both in Pondicherry and Tamil Nadu, a typical marvel even in created nations. This has happened in light of different limitations like logical/building comprehension of nature, financial matters of the plan to be actualized, institutional issues, absence of interstate coordination and acknowledgment by partners. It is prescribed to have an aggregate and normal shoreline administration get ready for the whole Pondicherry and the nearby Tamil Nadu drift so that here and now and long haul techniques can be drawn considering the drift altogether. The fleeting methodologies required at particular locales can be composed and incorporated in long haul systems, if a shoreline administration plan is readied. Pondicherry harbor is making a shortage in residue supply the northern drift. Sand bypassing completed by harbor experts for certain period could keep up the shoreline north of the harbor. Afterward, suspending the sand bypassing brought about loss of shorelines in the northern drift. The current investigation of satellite information recommends that parts of the littoral dregs are avoided actually to northern drift. While outlining the shore rebuilding plan for Pondicherry drift, the design of harbor and its connection to common bypassing of sand at harbor ought to be contemplated. Pondicherry wave atmosphere is impacted by both the SE and NE waves with incidental cyclonic tempests crossing the drift. The greatest surge level saw above tide is 0.7m with a tidal scope of 1.2 m. The waves comes nearer from SE course from April – September with mean heading 135 deg, while amid NE rainstorm, the bearing is 90 deg. The seaside streams are regular, coordinated to north amid SW storm and south amid NE rainstorm. The normal streams amid SW and NE rainstorm would be 0.3m/s and 0.5 m/s. The close shore streams created by waves take after comparative example like beach front ebbs and flows in Tamil Nadu drift, which is an additional favorable position in creating normal shore reclamation measures. An itemized consider led at Vellar estuary and Ennore demonstrates shoreline change administered by wave atmosphere and tidal impact is inconsequential. Low weight frameworks like occasions of 2007 can make critical harm drift and some of its progressions could be perpetual. The beach front security plot seawall worked along the Pondicherry town for length of 6 km should be assed painstakingly to keep away from further harm amid typhoon or low weight periods. As Pondicherry is known for its tourism/diversion, it is fitting to reestablish the normal shoreline by executing shoreline sustenance. At Ennore, sand dug from harbor to a degree of 3.5 million cum was put on north of harbor to counteract downdrift disintegration. The execution of shoreline support was surveyed in light of long haul information at Ennore which demonstrates food has provided sand to northern drift for time of 5 years and coastline was steady even after the development of harbor. Starting assessments demonstrate that sand to the degree of 3.0 million cum should be put north of the harbor for length of 600 m close to the Gandhi statue. The above alternative won't just help in picking up a characteristic shoreline additionally help in controlling the disintegration of the northern drift. The point by point outline of shoreline sustenance plan can be worked out in view of examinations. Additionally, eco-accommodating strategies and "delicate designing measures" to balance out the drift could be actualized alongside shoreline support for holding the sand and to reestablish the natural capacities and administrations that are given by sandy shoreline biological communities and upgrade employment open doors for the angling groups and increment incentive to the drift. A long haul and lasting arrangement can be found if both the Tamil Nadu and Pondicherry Governments together work towards a typical, long haul and reasonable shore rebuilding system. Short-term arrangements may should be executed, yet this needs to consider the long haul arrangements and ought to be "no-lament" arrangements. Worldwide there is presently expanding cases of substitution of hard structures like seawalls with milder alternatives, for example, shoreline support, sand bypassing, ridge planting and seaward submerged reefs. Hence, the general guideline of "working with nature" would be a superior approach for financially savvy and economical beach front insurance measures. Pondicherry necessities to consider current insurance practices which accomplish a more viable and reasonable methods for beach area security while additionally tending to neighborhood luxury and financial improvement viewpoints. It is most domineering to guarantee that the common development and stream of silt along the shoreline is kept up. Given the social and temperate significance of the Pondicherry shorelines, the beach front rebuilding choice ought to consider the assurance of land, structures, groundwater, biology, occupations and open and private foundation against future misfortune and harm brought about by Coastal Erosion. The shoreline rebuilding will essentially profit the beach front tenants living along the Pondicherry and adjacent Tamil Nadu drift including fishermen communities, the proprietors, administrators and representatives of these fishing communities, residences and other tourism related organizations and their workers. Be that as it may, for the most part it will profit every one of the inhabitants of this serene coastline whose youthful youngsters have never at any point seen its lovely shorelines. Nobody anticipated that the waves due with the rainstorm and violent wind would take away the regular shoreline leaving the area beach less.