NOPR Collection: Special Issue on Coastal Dynamics, Marine Environment & Resources, Ocean Engineering, Port and Harbour Engineering (Guest Editors: Jaya Kumar Seelam & R. Mani Murali)

Thermal pollution modelling of cooling water discharge into a closed creek system

2016-07-20T06:38:45Z

Title: Thermal pollution modelling of cooling water discharge into a closed creek system Authors: Buvaneshwari, S.; Ravichandran, Vijaya; Mudgal, B. V. Abstract: This paper is focused on the behaviour of the heated effluent discharged at an elevated temperature into the Ennore creek by North Chennai Thermal Power Station (NCTPS). Functioning of thermal power plants near tidal creeks and estuaries, due to the feasibility of intake and discharge of water for cooling poses serious environmental concern from heated water discharge due to the flow characteristics of the creek. Discharge of the heated effluent and its dispersion is a function of ebb and flood flow into the Ennore creek as the creek mouth remains closed for most part of the year. This study aims to investigate the dispersion characteristics of the heated effluent in the near-field and far-field under various discharge and dynamic conditions of the creek using calibrated hydrodynamic models and comparison with the field data measured during varying tidal conditions. Page(s): 1415-1421

Mean surface meteorological parameter characterization at Kavaratti, Lakshadweep Island, South-East Arabian Sea

2016-07-20T06:38:29Z

Title: Mean surface meteorological parameter characterization at Kavaratti, Lakshadweep Island, South-East Arabian Sea Authors: Kumar, Vijay; Mehra, Prakash; Nair, Balakrishnan; Agarvadekar, Yogesh; Luis, Ryan; Ghatge, Devika; Lobo, Shane; Harmalkar, Bharat Abstract: Soon after the south-west monsoon, mean surface meteorological parameters at the Kavaratti Island begin to change. Wind, which was south-west in direction during the monsoon period, turns to north-north and eventually to north-east direction with lesser intensity. Monthly mean wind speed in October was ~2 ms^-1 while in July it was~7 ms^-1. Monthly mean surface air pressure in October was ~1008 hPa as against ~1007 hPa in July. Surface air-temperature and relative humidity also exhibited similar variability. Monthly mean air temperature and humidity in October were ~28^°C, and ~76% respectively, while in July ~26^°C, and ~87% respectively were recorded. In general, wind was predominantly in the north/north-westerly direction throughout the year, except June-July during which a west/south-westerly winds was observed. Minimum atmospheric pressure occurs during June-July (southwest monsoon period) and the maximum during December-January (northeast monsoon period). Air temperature demonstrates steady increase from January to May before descending to minimum during July-August. During the observational period (2009) inverse relationships between barometric pressure and air-temperature was observed. Similar relationship between relative humidity and air-temperature was also noticed. Page(s): 1407-1414

Site selection for offshore wind farms along the Indian coast

2016-07-20T06:38:17Z

Title: Site selection for offshore wind farms along the Indian coast Authors: Murali, R. Mani; Vidya, P.J.; Modi, Poonam; Kumar, Seelam Jaya Abstract: This study deals with the location of the potential sites for offshore wind farms and also deals with the feasibility of installing offshore wind farms through scientific examination along the coast of India. Offshore wind energy is almost unexplored along the Indian coast. Potential and feasible regions need to be found and studied in detail. In this regard, few of the essential primary parameters such as bathymetry, wind velocity, proximity to the coast, ports, harbours, marine protected areas and marine sanctuaries were considered. Suitable sites for offshore wind farms were demarcated in a GIS environment. Weekly climatology (1999-2009) of wind speed was used to explore the seasonal wind potential. GIS analysis has brought out potential wind farms regions of 32,000 km² in north east Arabian Sea (Off Mumbai and Off Ratnagiri) where bathymetry is in the range of 20 m to 75 m. Wind velocity ranges between 1.9 m/s to 10.2 m/s in these regions. The second potential site has been identified at off Mangalore with 6490 km². The third prospective site is at Off Hooghly estuary. Page(s): 1401-1406

Repercussions of embarkation wharves in Lakshadweep Islands on coral communities and their ecology

2016-07-20T06:31:30Z

Title: Repercussions of embarkation wharves in Lakshadweep Islands on coral communities and their ecology Authors: Ravindran, J.; Manikandan, B.; Venkatesh, M.; Murali, R. Mani; Marimuthu, N.; Wafar, M.V.M. Abstract: Present study infers that the construction of embarkation wharves in four of the Lakshadweep islands (Agatti, Amini, Kavaratti and Minicoy) in the last 5 years was accompanied by a marked degradation of coral community structure and coral biodiversity. Reduction in live coral percent cover was significant, from 31% to 4.69% in Agatti, 24% to 5.92% in Minicoy, 22% to 3.49% in Amini and 30.5% to 4.4% in Kavaratti, with a simultaneous rise in the percent cover of other abiotic components. Species diversity of corals dominated by the massive reef-building corals was lost, affecting the structure and stability of the reef at these sites. Resilience potential of the reef became poor due to the monospecific colonization of corals belonging to very few genera like Pocillopora and Montipora. Reduction in coral cover and its diversity endangered the strength of the reef frame in the activity site and enhanced its vulnerability to the natural stress or calamities. Page(s): 1391-1400