A study of coastal transformation at Tuticorin as a result of emerged and submerged natural breakwaters of Van Island, Gulf of Mannar

Abstract

Similar to artificial offshore structures, natural structures such as an island also protect the low-lying shoreline and shape the pocket beaches. In the Gulf of Mannar, many long islands have formed protruding from shorelines. Formation of these indirect morphological structures depends upon a number of factors, such as the width of the island, offshore distance of the island to the morphological structure, supply of sediments and other geological conditions. The hydrodynamic conditions between Tuticorin Harbour and Van Island have changed because of various factors over the years. Van Island coral reef formation had attracted man-induced mining causing irreparable damage to the fragile ecosystem. The emerged natural breakwater and the submerged coral reef, together with the artificial breakwaters of Tuticorin Harbour, have been contributory to quantifiable change in hydrodynamic conditions around Tuticorin. As a result, the transmission of wave power to the shoreline has increased and the salient growth at Salaipatorri Point, Tuticorin, has started to recede. The bathymetric chart published in 1978 is used for all dimensions of Van Island and receding salient growth at Salaipatorri Point.

Environmental impact of submerged and emerged breakwaters

“…Tombolos and salients are produced by emerged breakwaters. The effectiveness of emerged breakwaters and the formation of tombolos or salients, are dependent on relationships amongst the shoreline-breakwater distance, the breakwater’s length, and the gap width ( Ramanujam and Sudarsan, 2003 ; Razak and Nor, 2018 ; Saidi et al., 2012a ). Saidi et al.…”

“…In some cases, submerged breakwaters induce neighboring shoreline erosion at both updrift and downdrift sides simultaneously, due to flanking phenomenon ( Torres-Freyermuth et al., 2019 ). Knowledge on salient and tombolo formations, depending on relationships amongst the shoreline-breakwater distance, the breakwater’s length, and the gap width, are well-established for emerged breakwaters ( Ramanujam and Sudarsan, 2003 ; Razak and Nor, 2018 ), but seems underdeveloped for submerged ones ( Kubowicz-Grajewska, 2015 ). Leeward sedimentation is enhanced by submerged breakwaters.…”

Classificação morfodinâmica das praias arenosas de Ipojuca (Pernambuco, Brasil) através da análise semântica de imagens de satélite pancromáticas

“…Neste último caso, os mesmos desenvolvem morfologia mais complexa, como manchas, estando associadas às saliências na costa, tal como observado em Porto de Galinhas. Os recifes têm o potencial de alterar a hidrodinâmica local e dissipar energia de onda, desempenhando assim, um importante papel na morfologia recente da costa (Ramanujam & Sudarsan, 2003). O nível de atenuação da energia de ondas, por sua vez, está relacionado à geometria e ao grau de submersão do corpo recifal (Shirlal & Manu, 2007;Borba, 2011).…”

Relevance of water quality index for groundwater quality evaluation: Thoothukudi District, Tamil Nadu, India

“…Further, it is observed that the concentration of major ions in groundwater of the area is high at many locations leading to unsuitability of groundwater for drinking, irrigation and domestic purposes. Many researchers had worked on the groundwater of Tuticorin District on various concepts, such as the land use and land cover pattern along the metal pollution in groundwater, to highlight the effect of the industrial (SIPCOT) effluents on Thoothukudi City (Puthiyasekar et al 2010), trace element concentration in the groundwater in Tuticorin City (Ravichandran 2003), coastal transformation of Tuticorin City (Ramanujam and Sudarsan 2003), hydrological influences on the water quality in Tamirabarani basin, depositional environment in and around Tamirabarani estuary of Tuticorin (Solai et al 2012) and hydrochemial characteristic of the coastal aquifer and aquifer characteristic along with its modeling around an industrial complex of Tuticorin district (Mondal et al 2009). Mondal et al (2008), Singaraja et al (2013), Singaraja (2015) and Selvam et al (2016) identified the groundwater quality to be rapidly deteriorating.…”