Study On Water Exchange And Oil Spill Removal Engineering Layout Of Harbor

Port is an important driving force of world economic growth as well as a place where direct conflicts between human activities and environment exist. Green Port is the dominant mode for future port development, how to reinforce environmental protection while the port planning, design, construction and operation is a key point for the implement of ‘port-human-nature’ harmony system.Based on the domestic and foreign research status analysis, this paper built a double-nested grid hydrodynamic model for Tianjin Port and Nangang Port. In order to realize the port hydrodynamic high-resolution simulation, open boundary condition is obtained from the simulated result of outer model. A detailed study had been conducted on water exchange capability(WEC) and oil spill drift-diffusion of East Harbor in Nangang Port Industrial Zone, respectively, by utilizing conservative tracer and Lagrangian particle tracking model considering the effects of wind and tide. The study focus on the WEC improvement between the East and West Harbor and the siting of the removal engineering based on the oil spill drift-diffusion of East Harbor. The main works and conclusions of this paper are as follow:East Harbor’s WEC is strong and it can finish the water update after 4.98 days. In the study of WEC, East Harbor was divided into 6 sub-regions according to characteristics of berth situation and the WEC of these sub-regions were compared. Meanwhile, a research on the effects of WEC improvement by engineering had been carried out with a method of artificial channelization applied in West Harbor. The result shows that WEC in different sub-regions are distinctly different from each other: WEC of the entrance part in East Harbor is strongest while the tail part is weakest. Wind direction also exerts an evident effect on WEC: north wind can improve the water exchange capacity(4.84 days), while south wind makes the opposite(5.89 days). WEC of West Harbor is much weaker than that of East Harbor, that may result from the longer distance between West Harbor and the entrance of Nangang Port. After the artificial channelization project, the West Harbor only needs 41 days to reach the same water update degree that takes 100 days before the project. The research showed that the application of artificial channelization can significantly improve the WEC of West Harbor.Besides, we built a Lagrangian particle tracking model based on Tianjin Port & Nangang Port hydrodynamic model with the introduction of the Brownian motion for oil spill drift-diffusion study. In the model, oil spill was abstracted into Lagrangian particle. Oil spill particles were initially set in sub-regions of East Harbor to simulate the transport path. Based on the simulation result, particle enrichment spots were chosen to set up clean-up devices. The cleaning efficiency of specific projects were compared considering the effect of wind, thus the best disposal spot was determined. Result shows that clean-up devices set up near the bulwark at the south of the entrance of Nangang Port Industrial Zone had a higher cleaning efficiency(generally up to more than 60%) and it can greatly reduce the clean-up costs. The cleaning efficiency of project 6 can be maintained at 80% regardless of the wind effect. It is efficient to set up clean-up devices at this spot in case of oil spill accidents.