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Beaches provide protection to residents living near the ocean by acting as a buffer against the high winds and waves of powerful storms or rough seas. It also helps the government to increase revenue and the development of infrastructure. Because beaches are very accessible to humans, it is very important to go through the demerits that are causing changes in the beaches and what steps can be taken to prevent the beaches from evolving. There are several studies indicating that there is an increase in the wave heights and wave periods along the Indian coasts, with maximum wave heights increasing by more than 30% in some of the locations. It is also found that at most of the locations along the east coast, wave periods are expected to increase by almost 20% whereas along the west coast, they are expected to increase by around 10% [Chowdhury et al. [2019] “Wave climate projections along the Indian coast,” Int. J. Climatol.https://doi.org/10.1002/joc.6096.]. This will alter the distribution of wave energy at the shoreline, swash-aligned beaches and additionally the design of coastal structures. It is particularly important to evaluate the wave characteristics and sediment transport which leads to erosion and/or siltation problems along the Indian coasts. In this paper, an extensive review on wave hydrodynamics, sediment transport and coastal erosion is compiled along the Indian coasts.

This study was carried out for a proposed fishery harbour in Wennappuwa, in Northwestern coastal stretch of Sri Lanka. Simulation of nearshore coastal processes such as hydrodynamic and sediment transport processes to ensure safe navigation and continues harbour operations are the main objective of this study. MIKE 21 modelling system was used to simulate hydrodynamics and sediment transport processes. With the hindcast nearshore wave climate, coastal processes were simulated for representative nearshore wave climate conditions. According to the MIKE 21 HD (Hydrodynamics) model results, it was identified that proposed port configuration is favored for its hydrodynamic performance. MIKE 21 ST (Sediment Transport) model was used to understand sediment transport patterns, especially at harbour entrance and approach channel to investigate the siltation possibilities. According to the simulated results which are based on average wave conditions, it was found that net sediment transport is directed from south to north direction. However, sediment transport movement has not supported to move sediment significantly in to the harbour through its entrance. Hence, sediment bypass can be expected through the harbour entrance with the proposed configuration. Thus, suitability of the harbour location and layout were justified with the numerically simulated results.

Sabine Bank, a transgressive shoal located 30 km off the Louisiana-Texas border, USA, has been considered as one of the plausible resources for re-nourishment of the adjacent barrier islands and beaches. Little has been reported on the bottom boundary layer dynamics and sediment transport from this shallow coastal environment. A comprehensive field investigation, coupled with numerical modeling, has been implemented. Wave and bottom boundary layer interactions were strongly associated with the passage of cold fronts across the region. Strong southerly/southeasterly wind regimes also contributed to the re-suspension and transport of sediments, even during summer season. Modification in bulk wave parameters due to two mining scenarios were computed using modified bathymetries and the result shows minimum impact from the proposed mining from the shoal crest. Sediment re-suspension intensity (RI) was computed and found to be high over the inner shelf and shoal during severe storms.