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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.

Like many of the tropical islands, the population of Andaman and Nicobar Islands, though not directly, relies predominantly upon rain water harvesting to quench their need and also depends on the groundwater sources. In the background of climate change, severity of hydrological cycle is much anticipated which may cause more extreme and unusual precipitation. It is quite essential to have other alternatives. Accordingly, groundwater could be exploited as a potential alternative. The present study intends to find out the potential groundwater source and estimate aquifer parameters in Kodiyaghat (KD) and Burmanallah (BN). As these areas are composed of very hard rock, Wenner-Schlumberger array has been used to carry out a 2D Electrical Resistivity Tomography survey to find out the fracture zone as well as to delineate the aquifer. KD and BN show maximum resistivity of 25,416 Ωm and 5985 Ωm indicate very hard rock terrain. Similarly, the minimum values of resistivity (21.6 Ωm and 30.4 Ωm) were observed at KD and BN define the presence of freshwater aquifers respectively. The aquifer identified was found to be at a depth of 5 m to 19.9 m at KD and 2.5 m to 20 m at BN. The calculated Hydraulic conductivity (14.85 m/day and 30.14 m/day), transmissivity (86.25 m 2 /day and 271.27 m 2 /day) and porosity (28.7% and 31.24%) values at KD and BN confirmed that, the located aquifer was of fresh ground water quality and can be utilized for drinking and house hold purposes. According to the results, almost 70% of the study area is hard rock terrain and 30% comes under potential aquifer zone. The results also show that, both the areas were characterized by Horst How to cite this paper: Sk, M., Ramanujam, N.,

Ground water in a shallow glacial till aquifer and a deeper weathered shale aquifer at a site near Rock Creek, Ohio has been contaminated with trichloroethylene (TCE). Evaluation of remedial alternatives indicated that a system of subsurface drains would be most effective for decontaminating the shallow ground water. The performance of the proposed subsurface drainage system for the shallow aquifer was simulated using finite‐element flow and transport models. Model results indicate that the drains should reduce TCE concentration in the shallow aquifer to about 8 ppb in approximately 24 years. A single extraction well was the selected alternative to remediate trichloroethylene concentrations in the deeper weathered shale aquifer. The performance of the proposed well was analyzed by an analytical method. Results of the analysis indicated that the extraction well should reduce contamination in less time than required for the shallow glacial till aquifer. Validation of the predicted performance of the remedial system will be assessed following installation of the system and collection of field data.