Coastal areas provide vital economic and recreational infrastructure. However, more extreme storms and rising seas owing to climate change are threatening this densely populated yet vulnerable area. To predict the impacts of these long-term processes accurately and to assure a perpetual ecosystem and sustainable land development, it is crucial to improve our fundamental understanding of the complex interactions between air-water-sediment system and human interventions, including small-scale and short-term nearshore processes. Using turbulence resolving and two-phase models, coastal & ocean engineering lab (COEL) at PKNU tackles the interconnectedness of large- to small-scales in sediment transport and hydrodynamics, particularly under extreme forcing (e.g., tsunamis and hurricanes). Detailed model results will lead to better parameterizations that can be included in larger-scale models, increasing the predictive capability for long-term coastal evolution.