Wave transformation at select locations along the Indian coast through measurements modelling and remote sensing

Abstract

Wind generated wave is the dominant forcing parameter for most of the nearshore newlineprocesses. Accurate and fine resolution (both spatial and temporal resolutions) wave newlineinformation is very essential for navigation, design of coastal/offshore structures and other marine activities. When waves generated by storms leave the zone of generation, they newlinecouple with locally generated waves, and create complex characteristics in the nearshore region. In the past, the source of wave information was mainly from ship observations. Advanced technologies led to the development of directional wave rider buoys and moored buoys which measure directional wave energy spectra at fixed point locations. Remote sensing sensors such as altimeter and scatterometer provide wind speed and wave height and wind speed and direction, respectively covering a large space. At times, in situ point newlinemeasurements as well as satellite observations may not be adequate for site specific studies newlinesuch as coastal development and beach stability. In this context, numerical modelling provides an opportunity to obtain the required wave information in fine resolution. Wave modelling results are also crucial to support forecasts and warnings to reduce risk of accidents and improve the efficiency of marine operations. Wave characteristics along the Indian coast have been studied by earlier researchers based newlineon ship observations, buoy measurements and remote sensing data. Most of these studies newlineare restricted to specific locations or periods. However, a complete description of sea states for all seasons and extreme events is still in demand. Further, interaction between multidirectional and multi-frequency waves (both swells and wind seas) is still recognized as a complex phenomenon in the coastal region, as the local wind seas play a major role in controlling the wave generation and propagation mechanisms in this region. Influence of sea breeze on wind sea generation along the west coast of India is dominant during premonsoon season.