Browsing by Author "Sivakholundu, K.M."

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    A description of tidal propagation in Hooghly estuary using numerical and analytical solutions /
    (Elsevier, 2018-09-18) Sivakholundu, K.M.
    A tidal propagation characteristic of Hooghly estuary is presented using numerical (ADCIRC) and analytical models (Friedrichs and Aubrey, 1994) along with observations. The analytical model is based on Friedrichs and Aubrey (1994) that simplifies the governing hydrodynamic equations greatly by retaining only those terms that are significant without losing the overall understanding of the propagation process. The analytical model is compared with corresponding 2-D depth averaged numerical (ADCIRC) model that retains all non-linear terms. The assumptions for simplification are found to be reasonable in the light of close agreement among analytical, numerical models and observations. A plan-form geometrical characteristic as well as hydrodynamic variable of the Hooghly has been compared with that of Delaware estuary for corroborating similar tidal propagation process. The Hooghly estuary has flood dominant asymmetric tidal propagation and a positive amplitude growth factor (μ). The observed tidal celerity (phase speed) on an average is slightly more than frictionless celerity. Using the conventions of Toffolon et al. (2006), Hooghly can be classified into ‘strongly convergent – strongly dissipative’ estuary. From the results it can be construed that the estuary is yet to stabilise and reach its equilibrium morphology. It can be close to its equilibrium as very little amplification (0.1 m) is noticed in the predominant semi-diurnal constituent M2 over 78 km (barely 7%) in the estuary. The parameters of width variation (γ) and the ratio between friction and inertia (χ) have been used to define the marginal condition for amplification. The relative position of Hooghly in terms of marginal condition is consistent with similar set of estuaries elsewhere that have been grouped using the above parameters.
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    Nearshore sediment exchange process around the cape comorin, the peninsular tip of india /
    (BioOne, 2024-12-20) Bragath, R.C.; Sivakholundu, K.M.
    Researchers have explored sediment transport's mechanism around the world's capes less than other coastal regions due to the multifaceted nearshore environment. Though recent research on nearshore sediment transport has advanced well, the complexity of sediment exchange around a Cape must be understood better. The coastal belt of Kanyakumari (Cape Comorin), India extends about 15 km on the east, bordering the Bay of Bengal, and about 55 km on the west, bordering the Arabian Sea with its confluence at the Indian Ocean. Unlike India's east and west coasts, the Kanyakumari coast follows a unique phenomenon in the coastal process, having peculiar wave climates resulting from the combined influences of ocean climate. The critical factor that causes changes in coastal configuration at the peninsular tip is the behavior of sediment transport. Most importantly, the exchange of sediments between the east and west coasts around this peninsular region is significant in determining the littoral drift pattern over the rest of the Indian coast. The present research work has studied the continuous movement of longshore currents over the peninsular tip using detailed active Littoral Environment Observation (LEO) for non-monsoon and monsoon seasons with varying wave climates and also relied on earlier studies taken up around the cape and assessed the significance of sediment transport around this littoral barrier. Field observations indicated that the littoral sediments reaching any potential barrier are likely to drift offshore and partly bypass to the adjacent cells within 20 m depth and partly deposited offshore during monsoon season. The sediments deposited offshore reach the beach again during fair weather, and such onshore movement builds up the stability of the eroded beach. During the ensuing monsoon period, these deposited sediments on the berm get eroded, carried into the sea, and deposited as offshore bars and maintain the beach's stability, providing enough sediment supply to the littoral cell system around the cape. The study highlights the significance of coastal dynamics and the interplay of nearshore sediment transport around the peninsular tip. We have also used mathematical modeling techniques to understand the hydrodynamic regime and the associated sediment exchange process.