Relation Dynamic Shear Stress and Wake Boat Waves Energy

Abstract

Coastal area is the most populated throughout the world due to its business activities especially those involves commercial or recreational vessels to bring people or goods. Inadvertently, heavily vessels traffic will create effect on shoreline, riverbank or estuaries in which resulting an erosion problem. Overcoming the problem, a few local state authorities are enforcing a regulation for the vessels to cruise along the coastline to minimize the erosion impact. This research was conducted to study the relationship of dynamic shear stress generated from wake boat and tidal flow induced energy at Kemaman river estuary, which located at Kemaman province, East Coast of Peninsular Malaysia. Evidence shows that erosion occurred along the riverbank, and it was confirmed that the vessels contribute to the erosion problem due to negligence of vessels’ speed. In addition, apart from the generated energy coming from the vessel, the dimension of the vessels also contributes to the erosion problem. The estimation of total energy created by each vessel is established by a formula through the relationship with wave energy under influenced of maximum wave height. The results indicate that increases in energy will increase the dynamic shear stress due to orbital wave velocity whereby it is a function of wave height generated by boat wave. Finally, the results also indicate addition minimum tidal flow rate and wake boat contributes higher dynamic shear stress as compared to mud bed shear stress. Therefore, it can be concluded that wake boat waves play a significant role in determining the riverbank erosion. The finding of this study serves some information as guidance to local state authority to impose regulation to community whom using the vessels to navigate through this estuary.