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Episodic extreme waves caused by cyclones can have catastrophic consequences for coastal zones, including drastic beach morphology changes. The present study analyzed the beach morphological changes from Kakinada to Konapapapeta on the southeast coast of India before, during, and after the tropical cyclone Phethai using field survey and numerical modeling. Beach profiles were collected using Trimble RTK GPS and shoreline tracking was performed with handheld GPS. Numerical modeling was carried out using MIKE software to estimate the sediment transport rate before, during, and after the cyclone. Although the intensity of the cyclone reduced to a deep depression before landfall, several morphological changes were observed. Erosion was higher in the northern sector, where the beach width was less, and prominent scarps were seen throughout this region after the cyclone. The inundation varied from 40 to 120 m during the cyclone due to a storm surge of 0.5 to 1 m. During the cyclone, significant wave heights reached up to 4 m. The gross sediment transport rate is 3 to 13 times greater during the cyclone period than during the non-cyclone period. The maximum gross sediment transport rate during the Phethai cyclone was 1040 m3/day. Sediment transport was estimated for the same site for the non-cyclone year 2019, and the gross transport rate was 26,174 m3. As it is projected that extreme events are likely to increase due to climate change, output from this type of study is vital to environmental managers to assess erosion and develop long-term mitigation plans. [ABSTRACT FROM AUTHOR]

Black, K.P.; Baba, M.; Mathew, J.; Kurian, N.P., and Ilic, A., 2021. Guidelines to prepare India's coast for climate change. Journal of Coastal Research, 37(6), 1117–1129. Coconut Creek (Florida), ISSN 0749-0208. India's first coastal protection guidelines for climate-change adaptation are described. The guidelines are holistic, recognizing the links between engineering, economic, physical, legal, social, environmental, and governmental intricacies. Robust protection solutions under climate change for millions of coastal residents may occur only when all these facets are improved within the complex regulatory, budgetary, and practical circumstances in India. Fifty-seven specific guidelines are presented in nine categories ranging from administrative to best-practice coastal protection. An "environmental softness ladder" that ranks coastal protection methods was developed as a scientific tool to guide policy development and project implementation. "Minimum floor level" for safe building was defined for each Indian coastal state using climate-change data produced for the study by Indian and international institutes. Beaches are more stable when the net sediment transport fluxes are close to neutral. "Grand schemes," which make large-scale changes to the coast rather than continuing with piecemeal localised works, are recommended. With diverse dynamics over a long coastline in India, the 4-year study engaged an exceptionally large number of experts, agencies, government bodies, development partners, and other stakeholders. [ABSTRACT FROM AUTHOR]

Black, K.P.; Kulkarni, K.B.; Naik, G.B.; Naik, M., and Mathew, J., 2021. Improving training wall orientation at river and estuary entrances. Journal of Coastal Research, 37(3), 484–493. Coconut Creek (Florida), ISSN 0749-0208. Natural river and estuary entrances adjust in response to the prevailing sedimentary and hydrodynamic environment. In India, during the monsoon rains, the ebb jet can be very large, firing water and sediments along a variable orientation to create the associated ebb deltas. However, once the entrance is trained onto a fixed alignment, this powerful jet "pump" can have adverse impacts. Due to downdrift erosion caused by the entrance training walls at the Old Mangalore Port (Karnataka, west coast of India), the breakwater was modified to reorient the ebb jet in the direction of the longshore drift. The goal was to beneficially use the natural pumping action to drive sand across the entrance without mechanical assistance. Three years of monitoring revealed improvements in downdrift beaches and navigational safety, while maintenance dredging has ceased. The entrance region has deepened by 854,166 m3 after reorienting the ebb jet over the period from October 2017 to February 2020. In contrast, the entrance shoaled by 160,305 m3 over the period from September 2008 to October 2017. The results are relevant to river and estuary entrances with moderate to strong river flows and/or tidal prism. [ABSTRACT FROM AUTHOR]

Saravanan, S. and Chandrasekar, N., 2015. Wave refraction pattern and littoral sediment transport along the SE Tamilnadu coast, India. The objective of the paper is to understand the wave refraction pattern and littoral sediment transport along the SE coast of India. There are areas of erosion and accretion observed along the coastal stretch that depend primarily the direction of wave approach, the wave period, and the wave refraction pattern. In the nearshore zone of the study area, the movement of sand alongshore is due to the action of waves and currents. Wave refraction is an important process responsible for effecting changes in coastal configuration. Based on this study, the wave convergent and divergent zones are identified with reference to wave refraction. Longshore sediment transport is higher in the northerly direction than in the southerly direction. The present study of littoral sediment transport implies that the beaches of Kanyakumari, Navaladi, and Ovari have greater transport rates. [ABSTRACT FROM AUTHOR]