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The north Chennai coast, on the east coast of India, experiences severe erosion caused by waves, and an area of the beach about 600 m wide has eroded over the past 120 years. To protect the seafront, natural stones were dumped by government agencies along the coast for a distance of about 6 km, and in the process, a short beach pocket 400 m long was left unprotected for various reasons. Because the property of a chemical factory located in this 400-m stretch of beach pocket suffered damage caused by erosion, and because the need for a wide beachfront was stressed by local fishermen, an alternative method of protecting the beach was suggested. The proposal involved construction of an S-type rubble sea wall about 100 m long on the southern end of the beach pocket. This paper discusses the numerical model studies conducted to determine the configuration of the S-type rubble sea wall and its effectiveness in beach protection. The model studies suggested a length of projection of 14 m with a radius of curvature of 310 m for the S-type sea wall to achieve the desired performance. Field studies conducted on the 40-m-wide and 400-m-long beach pocket with the 100-m-long S-type sea wall indicate that the sea wall is effective in protecting the beach. [ABSTRACT FROM AUTHOR]

The characteristic features of inter-seasonal variability of precipitation microphysics for the year 2019 over Mumbai and Chennai – the two urban-coastal cities of Indian sub-continent have been studied in this paper. The importance of choosing the regions lies in the fact that these two cities are well-known for the occurrences of severe rainfall events due to the effect of south-west and north-east monsoon during the summer and winter season of Indian sub-continent respectively. It has been observed that raindrops of diameter 2‐–4 mm dominate the summer rainfall over Chennai with respect to winter rainfall. Correspondingly, while comparing the two cities together, the impact of the south-west and north-east monsoon in conjunction with the interplay of the continental and maritime effect on the microphysics of precipitation over these cities is strongly visible in the analysis. The study reveals that the rainfall evolving from the continental clouds along with contrasting surface temperature produces distinct diurnal variation for the summer (winter) rainfall over Chennai (Mumbai) while such variations are not visible for the maritime clouds. It has been observed that the drops of larger diameter along with higher radar reflectivity dominated the summer rainfall of Chennai with respect to Mumbai. While for the winter rainfall, such distinct variations are visible only for higher rainfall regimes from 16 mm/h and above where the domination of larger drops is visible for the Mumbai rainfall. Thus the difference in surface temperature which in turn escalates the convective environment in the atmosphere can be termed as one of the important factors responsible for this inter-seasonal variability of precipitation microphysics. • Typical characteristics of rainfall and wind direction during inter-seasonal phases • Contrasting features of precipitation microphysics during summer and winter monsoon • Strong impact of continental and maritime clouds on precipitation microphysics • Important role of surface heating for diurnal variation of precipitation [ABSTRACT FROM AUTHOR]