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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]