http://nopr.niscair.res.in/handle/123456789/1820 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/1887 Title: Chemical flux to the coast of Bangladesh – a review <br/> <br/>Authors: Datta, Dilip K; Saha, Subrota K; Rahaman, Md Sayadur <br/> <br/>Abstract: This paper deals with the state of chemical flux to the coast of Bangladesh from ex-situ-, in-situ- point and non-point sources of geogenic and anthropogenic origin. Except for ex-situ chemical flux, no in-situ chemical flux to the coast of Bangladesh has been studied. The major elemental dissolved flux contributed by the Ganges-Brahmaputra-Meghna (GBM) river system to the coast of Bangladesh accounts for about ~5% (152 × 10⁶ t.yr⁻¹) of the annual global dissolved chemical flux to the oceans by rivers. This river system also contributes ~115 × 10³ t.yr⁻¹ of dissolved fluoride and ~105 × 10³ t.yr⁻¹ of dissolved phosphate to the coast of Bangladesh. The GBM river system is also one of the highest sediment dispersal systems of the world and transports about 1060 million tons of sediments to the coast of Bangladesh each year. Studies showed that DDT in zooplankton, fish and bottom sediments from the Bay of Bengal also occurs in the range of 4.0 to 5.9 ppb, 0.3 to 8.6 ppb and 0.032 to 720 ppb respectively. Since the coastal ecosystems are sensitive to chemical changes in the aquatic environment, estimation of chemical flux to the coast of Bangladesh is important. <br/> <br/>Page(s): 214-219 Thu, 29 May 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1886 Title: Comparative investigation on physico-chemical properties of the coral reef and seagrass ecosystems of the Palk Bay <br/> <br/>Authors: Sridhar, R.; Thangaradjou, T.; Kannan, L. <br/> <br/>Abstract: Coral reef and seagrass ecosystems separated by a distance of 25 km in the Palk Bay region were investigated for their physico-chemical properties. Monthly variations of different parameters investigated are as follows; air temperature (27 - 35 ºC), surface water temperature (25.0 - 31.5ºC), LEC (0.54 - 1.22 k), salinity (28.0 - 36.0 ‰), pH (7.0 - 8.2), DO (3.15 - 6.68 mll⁻¹), nitrate (0.25 - 7.3 µM), nitrite (0.03 - 2.91 μM), inorganic phosphate (0.12 - 4.1 μM), reactive silicate (0.6 - 7.4 μM) and POC (0.28 - 3.25 mg C l⁻¹). There is distinct spatial variation on the above parameters between the stations. The present study had elucidated that the ecosystems like coral reefs and seagrass are prefer specific environmental conditions for their survival. <br/> <br/>Page(s): 207-213 Thu, 29 May 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1885 Title: Identification of the geochemical processes in coastal groundwater using hydrogeochemical and isotopic data: A Case study of the Gadilam river basin in southern India <br/> <br/>Authors: Prasanna, M.V; Chidambaram, S; Vasu, K; Hameed, Shahul A; Warrier, Unnikrishna C; Srinivasamoorthy, K; Anandhan, P; Peter, John A <br/> <br/>Abstract: The Gadilam river basin in Tamilnadu is characterized by different geological formation viz. Archaean, Cretaceous, Tertiary to Recent Alluvium and groundwater serves as the major source for domestic, agriculture and other water-related activities. Forty four groundwater samples were collected during summer and post monsoon. Twenty three samples were analysed for stable isotopes (δ¹⁸O and δD). Geochemical signatures of groundwater were used to identify the chemical processes that control hydrogeochemsitry. Chemical parameters of groundwater such as pH, EC, TDS, Na⁺, K⁺, Ca⁺, Mg⁺, HCO₃⁻, SO₄⁻, PO₄⁻ and H₄SiO₄ were determined. Interpretation of hydrogeochemical data ascribes that secondary leaching, saline water intrusion and anthropogenic impact in this regime. Interpretation of δ¹⁸O and δD indicates recharge from the meteoric water in Tertiary aquifer and from evaporated water in Alluvium aquifer. <br/> <br/>Page(s): 200-206 Thu, 29 May 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/1884 Title: The composition of groundwaters of Muraviov-Amursky Peninsula, Primorye, Russia <br/> <br/>Authors: Chudaeva, V A; Chudaev, O V; Yurchenko, S G; Sugimory, K; Matsuo, M; Kuno, A <br/> <br/>Abstract: Seawater intrusion, composition and quality of the shallow ground water in the south of Primorye region had been investigated. The Muraviov-Amursky peninsula is a middle mountain area (up to 400 m). The rocks in this area are presented by Permian volcanic, sedimentary, and granite rocks as well as Triassic sediments. Water had been included in a fracturated zone. The water table is located at depths ranging from less than 1 meter to more 20 m. The changes is depending on seasonal and atmospheric precipitation that varies between 1000-1200 mm/y. Values of pH ranging from 5.4-8.4, main ions composition is mixed with HCO₃-Ca, Na – in granite rocks. Sea water intrusions had been examined by chemical and stable isotopes data. <br/> <br/>Page(s): 193-199 Thu, 29 May 2008 22:58:59 GMT