Remote Sensing And Numerical Simulation Of Suspended Sediment Pollution Caused By Offshore Transportation Hub Construction

Since the latter half of last century, a new tide of large offshore transportation hub construction is springing up in the world, including offshore airports, deepwater ports and sea-crossing bridges and tunnels. Compared with the previous conventional projects, the construction of offshore transportation hub has more effect on marine environmental pollution, especially on suspended sediment pollution of wider area and longer duration. However, these construction projects of huge size are lack of effective monitoring means and analysis methods. So far, it is difficult to judge marine environment effect due to the insufficient relevant research. To overcome space-time limitation of field research, as the background of Dalian offshore airport construction, the paper uses remote sensing technology to implement large-range and multi-temporal monitoring of suspended sediment pollution caused by offshore transportation hub construction, and tries to objectively reflect the distribution and variation of suspended sediment during construction. Using numerical simulation to predict suspended sediment diffusion process in different tidal current, and combining with retrieval results and sampling verification, the paper realizes synergistic analysis of remote sensing and numerical simulation for suspended sediment pollution. With the synergistic method, the impact range and degree of suspended sediment during construction can be mastered timely and fully. The monitoring method above has the value of practical application for making environmental measures and minimising the pollution caused by offshore projects construction.The major works accomplished and achievements of this study are as follows:(1) Using numerical simulation to predict change of tidal current and suspended sediment diffusion process. The two-dimensional flow mathematical model is developed and the water quality is used to predict the strength and distribution of suspended sediment during different tidal current.(2) The suspended sediment concentration is retrieved based on HJ-1A/1B-CCD data, which is verified by the in situ measurement data.(3) Comparative analysis of the results of numerical simulation and remote inversion, the paper tries to explore the relationship between the flow field change and suspended sediment distribution by remote inversion, and tempts to infer the dynamic changes of water pollution during construction.