IN-SITU OBSERVATION OF HYDRO-SEDIMENT DYNAMICS ON STEEPLY SLOPING SEABED IN DEEP WATER

Evaluating the local sediment balance is a crucial component of effective coastal erosion management. Traditionally, we set a depth of closure in a target coastal area, representing the point beyond which sediment transport is assumed to be minimal. This concept helps us maintain the assumption that the sediment budget remains balanced landward. However, during extreme events, sediment transport can exceed this depth, leading to a loss of coastal sediments. This scenario is particularly relevant for coasts adjacent to a steep offshore slope, where sediments released onto the slope may never return to the upper coast. The process of downward sediment transport in the lower shoreface remains poorly understood, primarily due to the inherent challenges associated with in-situ observations of sediment dynamics in deep water. Our study aims to explore the characteristics of near-bed flows and sediment transport on steep slopes in deep water.