System simulation of the eco-environment effects on the coastal zone of Bohai Bay, China

During the past few decades, there has been an increase in the number of coastal land reclamation projects for residential, commercial and industrial purposes in more and more coastal cities of China, which led to the destruction of the wetlands and loss of the sensitive marine habitats. Meanwhile, the influences and nature of these projects attract widespread public and academic concern. For identifying the trend of landscape (esp. Coastal reclamation) and ecological environment changes, understanding of which interacted, and offering a general science for development of regional plans. In paper, a case study was carried out in Bohai Bay area, based on the analysis of remote sensing data. Landuse maps were created for 1954, 1970, 1981, 1990, 2000 and 2010. Landscape metrics were calculated and illustrated that the degree of reclamation changes were linked to the hydrodynamic environment and macrobenthos community. The results indicated that the worst of the loss of initial areas occurred during 1954-1970, with 65.6% lost mostly to salt field; to 2010, Coastal reclamation area increased more than 200km2 as artificial landscape. In Bohai Bay, for one thing, the numerical simulation of tidal current field in 2003 and 2010 respectively showed that the flow velocity in offshore became faster (from 2-5 cm/s to 10-20 cm/s), the flow direction seem to go astray and it was not conducive to the spread of pollutants and degradation, due to the significant changes of coastline; For another, the analysis of the dominant macobenthos from 1958 to 2012 showed that Musculus senhousei (Benson, 1842) as a disturbance tolerant species spread very fast and had been the predominant species in the recent years.