Environmental Evolution And Countermeasure Research Of Lianyungang Offshore Area

Lianyungang that lies in the middle of our country's seacoast is the east point of New Euro-Asia continental land bridge. During the recent two decades, with economic developing, Lianyungang offshore area has achieved much more than before in port construction, offshore industry, coastal touring and coastal breeding. But as the same time the coastal environment is also deteriorated.At present time, the systematic and comprehensive research on the influence of eco-environment is short of due to the exploiture. And the single project environmental impact assessment is not enough for marine eco-environment impact. Therefore, a synthesis investigation on chemical elements of seawater, sediments and biology is carried out on October, 2005, and indices of ocean ecological effects have been observed, comparing with the historical investigation, the accumulative impact is researched in the three sea areas which separated by alkali factory, West Waterbreak and nuclear power plant. Several achievements have been made as follows:(1) The exploitation of the offshore areas in Lianyungang has partly changed the properties and tidal current field of offshore areas, which reduce the exchange capability and the physical self-purification capacity of the water, thus influencing the water quality of this area. The study shows that the water quality around the power plant is the best, while the water around the port is the worst, the three areas are whole lightly polluted; The chief pollutant of the harbor and nuclear power plant offshore area is active phosphate, followed by oil and inorganic nitrogen, the chief pollutant of the alkali factory offshore area is inorganic nitrogen, next is active phosphate and COD_Mn, heavy metal pollution in each area is relatively slight.(2) The research indicates that Lianyungang area is the modern underwater shoal, engendering by discard yellow river, sentiment granularity is relatively fine, and mainly consists of silt clay, substance source is relatively single. The far-forth shore area was typical of main residual sand, with transition zone of modern sediments and residual sediments in the middle, the substance source begin to be various, and the particle size became coarse. West Waterbreak blocking the sea has changed the former run-through channel into semi-closed manual gulf, current and dynamic conditions are changed, and presented in the grains size distribution of sediments, which leads to change of quality of bottom. Meanwhile, the two mud throwing zone in the port areas are influenced by wave and current, thus changing the grain size distribution of quality of bottom.(3) Judging from the research, the sediment rate in Lianyungang area was gradually decreased from south to north, which is the main result of natural environment changed both in time and space, another is the result of human activity to natural environment. The research concludes that the sediment environment before West Waterbreak is fairly constant. While it was not constant after the engineering out...