The Research On Marine Environmental Impact On The Qingdao Marine Dumping Site Of Long-term Dumping Activity

Qingdao Jiaozhou Bay marine dumping area is located outside the Jiaozhou Bay, Huangdao District east of the Xuejiadao. The dumping area waters has been reduced to:35°59’07"～35°58’39"N,120°18’30"～12°020’00"E since April4,2003according to the depth reasons,with other waters temporarily closed to stop using. This paper focuses on the statistical analysis on water quality, sediment and biological survey during the eight years(20042011) after Qingdao dumping area narrowing, and conducts research on regional water environment, sediment and ecological environment changes, meanwhile making numerical simulation for the dredged sediment diffusion.According to the dumping area water quality investigation during2004-2011, water surface layer and bottom layer pH, Salinity, suspended solids, COD, DO, DIN, phosphate, and heavy metals Cu,Pb,Zn,Cd and Hg showed relatively the same change trend. Inorganic nitrogen in the water, phosphate, heavy metals (except for lead and zinc outside) content showed a certain degree of growth, from a certain extent that dumping area water quality has decreased.The sediments type of this area is mainly silty clay, clay silt. Surface sediment t basic little change in sediment quality. Cu,Pb,Cd,Zn,Cr in the trend is similar.Before2007, the contents were showing a certain fluctuation trend, after2007, the content change is relatively smooth. Mercury investigation in the period of content has been showed large fluctuations. In8years, organic carbon, oil and sulphide content shows a certain degree of slow growth trend.As to the marine phytoplankton survey during2004-2011,species number basically maintained at a stable level, while the zooplankton species composition shows obvious fluctuation, biomass also presents the corresponding variation characteristics. The number of benthic species was some fluctuation in2008, the number of its kind since2008has been an increasing trend.The maximum depth of dumping area waters within the measuring area is28.7m, with the minimum depth of less than4.0m. By dumping the effects in the island, bridges formed between three relatively distinct steep slope of the hill, in the shape of ellipse, in2005compared with average depth, shallow about6.7m, the largest shallow about14.5m. On a bridge near the island of depth variation is relatively small, changes in the range of I-2m; the northern area closed after nearly8years of use in closed, under the action of tide wandering, continuous erosion, leading to the formation of a new stable topography, relatively deep about2m.According to the prediction results of numerical simulation of suspended sediment in dredged sediment, the dumping point sediment transport and diffusion is mainly the direction of SW and NE after dumping,. Whether single or continuous ship dumping dumping, l0mg/L contour line (super two quality standards) farthest diffusion is not more than2.4km,100mg/L contour line (super three quality standards) farthest diffusion not exceeding0.7km. It is concluded that the dumping activities on the sea water quality have an impact,but in the limited range. And also explains that the investigation results are similar as the monitoring points of the closed dumping zone and dumped area are all in the sphere of influence.