Oyster aquaculture farm(OAF)with dense wooden stakes,one of the prevalent large-scale marine culture facilities in estuaries,has the potential to influence estuarine hydrodynamics,sediment dynamics,geomorphological ev...Oyster aquaculture farm(OAF)with dense wooden stakes,one of the prevalent large-scale marine culture facilities in estuaries,has the potential to influence estuarine hydrodynamics,sediment dynamics,geomorphological evolution,and sustainable development.This study investigated these impacts in the Moyang River Estuary(Guangdong Province,China)by combining a two-dimentional coupled current-wave-sediment numerical model with field observations based on the TELEMAC-MASCARET numerical simulation system.The wooden stakes of OAF were represented as rigid cylinders in the model,and key parameters were calibrated through field observations,including stake diameter(0.1 m),spacing(3 m),height(6 m),and drag coefficient.Simulations comparing scenarios with and without OAF quantified the responses of sediment dynamics to estuarine OAF.Tidal currents in the channel were strengthened,with velocity increased by 20%-70%,while currents within the OAF weakened,with the maximum reduction exceeding 0.45 m/s.Significant wave height rapidly attenuated within OAF,with the wave attenuation coefficient exceeding 50%.Concurrently,due to the effects of stronger ebb dynamics caused by OAF,sediments in the channel were eroded,inducing a larger rate of seaward residual transport over a tidal cycle.Additionally,more sediments in the middle bar were resuspended,promoting the formation of a high-concentration zone of suspended sediment(estuarine turbidity maximum)during the ebb period.These changes in sediment dynamics caused by OAF significantly influenced the geomorphological evolution of the mouth bar,driving seaward channel extension and deepening,while causing progressive vertical accretion and lateral expansion in the top and outer slope of the middle bar.Sediment resuspension and redistribution within the mouth bar facilitated net transport and redeposition along the OAF periphery.Furthermore,it is crucial to appropriately increase the stakes spacing in the management of oyster farms to ensure a stable flow of water within the OAF.These findings provide a transferable framework for investigating sediment dynamics and a scientific basis for evaluating marine aquaculture practices in other estuaries with OAF or similar anthropogenic structures worldwide.展开更多
基金The Yangjiang Waterway Affairs Center of Guangdong Province Program under contract No.HLSJCG-20220103the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Program under contract No.SML2023SP220.
文摘Oyster aquaculture farm(OAF)with dense wooden stakes,one of the prevalent large-scale marine culture facilities in estuaries,has the potential to influence estuarine hydrodynamics,sediment dynamics,geomorphological evolution,and sustainable development.This study investigated these impacts in the Moyang River Estuary(Guangdong Province,China)by combining a two-dimentional coupled current-wave-sediment numerical model with field observations based on the TELEMAC-MASCARET numerical simulation system.The wooden stakes of OAF were represented as rigid cylinders in the model,and key parameters were calibrated through field observations,including stake diameter(0.1 m),spacing(3 m),height(6 m),and drag coefficient.Simulations comparing scenarios with and without OAF quantified the responses of sediment dynamics to estuarine OAF.Tidal currents in the channel were strengthened,with velocity increased by 20%-70%,while currents within the OAF weakened,with the maximum reduction exceeding 0.45 m/s.Significant wave height rapidly attenuated within OAF,with the wave attenuation coefficient exceeding 50%.Concurrently,due to the effects of stronger ebb dynamics caused by OAF,sediments in the channel were eroded,inducing a larger rate of seaward residual transport over a tidal cycle.Additionally,more sediments in the middle bar were resuspended,promoting the formation of a high-concentration zone of suspended sediment(estuarine turbidity maximum)during the ebb period.These changes in sediment dynamics caused by OAF significantly influenced the geomorphological evolution of the mouth bar,driving seaward channel extension and deepening,while causing progressive vertical accretion and lateral expansion in the top and outer slope of the middle bar.Sediment resuspension and redistribution within the mouth bar facilitated net transport and redeposition along the OAF periphery.Furthermore,it is crucial to appropriately increase the stakes spacing in the management of oyster farms to ensure a stable flow of water within the OAF.These findings provide a transferable framework for investigating sediment dynamics and a scientific basis for evaluating marine aquaculture practices in other estuaries with OAF or similar anthropogenic structures worldwide.
