Study On Characteristics Of Aquatic Ecological Environment Of Tianjin Coastal Water And Its Spatial Decision Support System

With the development of economy and the increase of pollutant emission alongcoastal areas, the coastal ecological environment is facing tremendous pressure. Thestudy on coastal ecological characteristics is of great significance for theunderstanding of marine ecological processes, protecting coastal aquatic ecosystemand marine management.Due to the complexity of the coastal eco-environment, the study of coastalecological environment faces with many challenges. In order to promote the healthydevelopment of the Tianjin coastal ecological environment, we studied the ecologicalcharacteristics of Tianjin coastal area systematically and developed the Tianjin coastalecological environment spatial decision support system.Firstly, the spatiotemporal distribution characteristics of eutrophication in Tianjincoastal waters were analysed using the properly selected temporal-spatial analysismethods. The results indicate that the annual variation of eutrophication showsdownward trend in the earlier stage and upward trend later, and shows the spatialvariation trend of decreasing from near-shore to off-shore. The spatial and temporaltrends mainly influenced by the land-source discharges.Secondly, in order to overcome the shortcomings of the traditional ecologicalenvironment quality evaluation method, such as reflecting the one-sided informationand tending distortion, this study proposed a multi-level gray relationalcomprehensive evaluation method to evaluate the ecological environment quality ofTianjin coastal waters. The result shows that the overall quality of the environment isnot optimistic, and the environmental qualities of the four functional areas aresignificantly different from each other.Thirdly, in view of the limitations of the traditional eco-hydrodynamics modelsto treat the uncertainty in the eco-environment, an uncertainty reasoning model, basedon linking structural equation modeling (SEM) with Bayesian network (BN), wasdeveloped. The SEM-BN model was applied to study the phytoplankton dynamics inTianjin coastal area, with satisfied results being obtained.Finally, based on the characteristics of Tianjin coastal ecological environment,the Tianjin coastal ecological environment spatial decision support system was developed to provide an integrate research platform for studying Tianjin coastalecological environment. Meanwhile, the traditional data management and modelintegration approach was improved for efficient management of ecological data andecological models.