ON THE USE OF ACOUSTICS FOR MEASURING SHALLOW-WATER SUSPENDED SEDIMENT PROCESSES

Acoustics have the promise of being able to have a significant impact on our understanding of coastal sedimentary processes, which play such an important role in the dynamics of the coastal and shallow water en vironment. Due to this, the application of acoustics for remotely meas uring suspended sediments, over ranges from metres to tens of metres, is gaining acceptance within the sediment community. This recognition of the use of acoustics to the area of sediment processes is based on advances which have been made over the past decade in our understandin g of the interaction of sound with marine suspended sediments, and als o due to ongoing field observations which have shown the unique abilit y of the acoustic technique to measure suspended sediment profiles. In the present work acoustic measurements of suspended sediments have be en conducted at 1, 2.5, 3, and 5 MHz in a number of different shallow water environments. The interpretation of the acoustic data to obtain suspended sediment concentration is presented, and some of the difficu lties when inverting the acoustic information to obtain the suspended load are considered. Some discussion is also given to future uses of a coustics for studying sediment processes, and how we may utilize the a pplication of underwater sound to manage our coastal environment more effectively.