Research Publications
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Item Evaluation of river regulatory measures in hughly estuary using tidal asymmetry characteristics(IEEE, 2006) Sivakholundu, K. M.; Kathiroli S.; Mani J. S.; Idichandy V. G.Tidal asymmetry has a profound effect on estuarine hydrodynamics and sedimentation pattern. The information of tidal asymmetry can be a useful tool to evaluate the flow pattern in shallow estuary and characterize the dominance of flood or ebb flow. The effects of features (like obstructions, depressions, etc.) and discharge variation in a theoretical channel section is simulated to quantify the parameters of tidal asymmetry. A set of proposed river regulatory measures in a shallow estuary (Hughly, India) was taken up for evaluation using tidal asymmetry parameters to check whether this may be used as additional tool. The indications provided (flood dominance and hence sediment importing regime) with asymmetry parameters do match with field conditions (based on bathymetry survey data). The asymmetry parameters may be put to use to evaluate the change in flood/ebb dominance in relative terms in a given section.Item Estuarine channel stability assessment through tidal asymmetry parameters(Journal of Coastal Research, 2009-03) Sivakholundu, K. M.; Mani J. S.; Idichandy V. G.; Kathiroli S.In an estuarine channel the tidal asymmetry, sediment transport, and morphology are interconnected. To maintain a stable channel, we need to take tidal asymmetry into account. A relationship connecting tidal asymmetry and sediment transport rate has been used to evaluate the relative merits of channel modification through numerical simulations. Two criteria have been identified for ensuring the channel stability: (a) maintaining ebb dominance and (b) minimizing the spatial gradient in the net sediment transport function ⟨q⟩. Using these criteria for a test case, we have evaluated Hooghly estuary (east coast, India), where heavy sedimentation is experienced and a permanent solution is needed. The approach provides better insight into the sedimentation pattern in a semidiurnal tidal process in a shallow estuary with braided channels. Among the factors affecting tidal asymmetry, the relative phase difference (β) between M2 and M4 current constituents has a major influence and is thus responsible for the sedimentation pattern. Through numerical study it was found that a combination of deepened, uniform channel with enhanced ebb flow led to a favorable β, indicating less deposition.Item Application of parametric acoustics for shallow-water near-surface geophysical investigations(IEEE, 2006-05) Vasudevan, Manoj; Sivakholundu, K. M.; Venkata Rao, D.; Kathiroli, S.Shallow-water near-surface geophysical investigations were carried out, under two different scenarios - one to assess the status of a pipeline in the West coast and the other to assess the effect of water-injection dredging in the East coast of India. In both these investigations, Parametric Sediment Echo Sounder (SES-2000), a system developed by Innomar Technologie GmbH, which makes use of the parametric acoustical effect, was used. In the former case, profiles were taken across a pipeline at regular intervals to determine whether it was buried or exposed. The parametric system produces a 2D geo-acoustic section in which the pipe is indicated by a hyperbolic curve. The exposed height or buried depth of the pipeline at a crossing is then estimated. This investigation could, also, reveal the geomorphologic changes in the immediate vicinity of the pipeline. In the latter case, parametric acoustics was utilized to provide supplementary results for the assessment of water-injection dredging. Parametric acoustic data could expose the abrupt termination of certain near-seabed layer interfaces and sediment accumulations along steep slope, quite convincingly. SES-2000 proved to be handy to investigate the near-surface sub-seabed, especially in areas where conventional or popular methods find practical difficulties to be carried out.Item A new archaeological find in the Gulf of Cambay, Gujarat(Journal of the Geological Society of India, 2002) Kathiroli, S.; Badrinarayanan, S.; Venkata Rao, D.; Rajaguru, S.; Sivakholundu, K. M.; Sasisekaran, B.Detailed underwater surveys carried out in the Gulf of Cambay, about 20 km west of Hazira, deploying side scan sonar and sub bottom profiler brought to light, the presence of a submerged palaeochannel traceable to a length of 9 km. Associated with this on either side are basement like features found in a grid pattern at water depths of 20-40 m. Sub-surface sampling carried out with dredge and grab sampler revealed stone artefacts, potsherds, hearth pieces, animal bones and human teeth embedded in fluvial sands and silts. In the upper part of the deposit, a carbonised wooden log was found and dated to around 9500 years BP by 14C method. Marine magnetic survey carried-out does not indicate the presence of any major metallic debrislobjects. This appears to be one of the early records of prehistoric human activity of early Holocene age in the marine environment of India.Item Intra-annual studies of mixed layer depth in the Arabian Sea using a 3 ½ layer Indian ocean model(Bentham Open, 2009-09-04) Patnaik, K. V. K. R. K.; Sreenivas, P.; Venkata Ramu, Ch.; Arun Kumar, S. V. V.; Prasad, K. V. S. R.Mixed layer is the upper layer of the ocean, where significant physical, chemical and biological activities take place. Knowledge of mixed layer depth variability is important in the studies of air-sea interaction, acoustic propagation, heat transport and fisheries. The Arabian Sea experiences extremes in atmospheric forcing that lead to intra-annual and inter-annual variability. Since the climatic conditions over the Arabian Sea are highly variable, the mixed layer depth also changes seasonally. Hence the intra-annual variability of mixed layer depth in the Arabian Sea has been examined using 3 ½ layer Indian Ocean model. The model is integrated for 8 years (1993–2000) with annually varying monthly averaged winds derived from ERS-2 scatterometer. In addition to this data, inter annually varying monthly averaged satellite estimates of precipitation from Global Precipitation Climatology were also incorporated in the model. Model results show a steady deepening of mixed layer depth in the central Arabian Sea during southwest monsoon period. The model shows its capability to predict the shallow mixed layer depths caused by coastal upwelling off Somalia during southwest monsoon period and is able to capture the Lakshadweep high/low as it predicted successfully the deeper/shallow mixed layer observed during these periods.Item Role of storytelling in learning in the context of knowledge management system(IIS, 2007) Surulinathi, M.; Chavan, S.B.; Devendrappa, T.M.Humans are telling stories since ancient, and there is a resurgence of interest in the art among today’s organizational leaders. What is new is the purposeful use of narrative to achieve a practical outcome. This paper focuses on some leading concept like learning style, learning methods, learning tools in knowledge management system. Storytelling will become a key ingredient in managing communications, education, training, innovation and sharing knowledge in the digital learning environment. Storytelling is the act of telling a story in an entertaining, impressive or dramatic way. “Audience want an unexpected gift at an unexpected time”. Adding feeling or emotion is probably most important. How do we do it? Generally we remember the feeling of the event or imagine what our characters might be feeling and then adjust our 'delivery' accordingly. This articles focused on features of storytelling and how the software facilitate to telling the story.null.listelement.badge Significance of income generation activities under micro-finance: A study of micro-finance groups in wayanad district, kerala(Institute for Social and Economic Change, 2005) Mathew, Emil.The present paper discusses the necessity of promoting income-generating activities (IGAs) under micro-finance programmes. Under micro-finance programmes, the principle of joint liability ensures access to credit. In the absence of remunerative IGAs, peer pressure forces the members to borrow loans from various sources at the time of repayment and results in indebtedness. The present paper examines the factors influencing the members to undertake IGAs and puts forth some policies to promote productive activities.null.listelement.badge Does repayment indicate the success of micro-finance programme(Institute for Social and Economic Change, 2006) Mathew, Emil.This paper examines the patterns of loan utilisation and repayment among microfinance group members of Wayanad district of Kerala. It argues that 100 per cent repayment by members need not always indicate the success of group lending. As majority of the members have not undertaken income generating activities, the fear of social sanction and repeated interactions put pressure on them to depend on micro-finance loans at the time of repayment. The absence of alternative credit sources increases the financial dependence of the members over a period of their stay in micro-finance programme.