Tendency and Causes Analysis of Marine Water Quality of Daya Bay

Base on the monitoring data of 9 major pollutants of Daya Bay from 1992 to 2009,this article analyzed the spatial and temporal trends of marine water quality of Daya Bay,and discussed the causes from two aspects: the distribution of the nearby pollution sources and the water exchange capacity.Results showed that the water quality over the years maintained at a stable level,and didn't grow with the pollution emissions,which was found owning to the strong water exchange capacity of Daya Bay,pollutants poured into the bay were quickly diluted and diffused and the water quality kept stable although the sources were on the rise.The water quality of different areas showed large diversity,some regions were good,while some were contaminated and worsening,which was related to the distribution of the pollution sources and the different water exchange capacity of each area.