研究期間：10108~10207;Hydrodynamics is important for modeling and monitoring the geological, biogeochemical, and biological process in a coral reefs environment. Based on the up-to-date literature review and the PI’s recent experiences, hydrodynamic flows over shallow fringing coal reefs exposed under waves are largely unexplored. The present research project is therefore prompted to conduct field observations of hydrodynamics over the fringing coral reefs at Hobihu, Nan-Wan Bay, southern Taiwan. The study site is chosen due to its abundance of multi-scale hydrodynamics. Indeed, the present proposed project is a successive project of the PI’s last NSC project (originally proposed as a three-year project, but granted for one year). The granted one-year NSC research project focuses on studying the local vertical distribution of turbulence properties, coherent structure, and mechanism of turbulence transport within the fringing coral reefs. However, it is unclear what the dominant driving source of the current flow is over the shallow fringing reefs. The tidally induced circulation and upwelling of cold water may intrude into the shallow region causes temperature drop. Recent studies showed that mean currents near Nan-Wan bay exhibit different patterns in summer and winter; therefore, this project will study how the unsteady currents affect the mixing in the water column from the observed data collected in summer and winter. In summary, several scientific questions this project is seeking to investigate include: (1) Mechanism driving the flow motions over the fringing reefs in summer and winter; (2) Interaction of multi-scale flow motions (tidally induced current, wave-driven current, wave-induced oscillatory flow, bottom-induced turbulence etc.); (3) Wave-phase depended turbulent quantities in coral reefs; (4) Wave energy dissipation rate and friction factor over the coral reefs.
