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In recent years, coastal development, especially the development of the mudflat resources, coastal tourism, the rise of human activities Guangxi islands, coastal zone has undergone great changes in this article by the Guangxi typical offshore island - Weizhou SURFACE SEDIMENT the typical shore island - the gantry Island and Nishimura Island intertidal zone analysis, particle size analysis, the analysis of organic carbon and calcium carbonate, the following main conclusions and understanding: Weizhou intertidal zone of surface sediments the heavy metal content of the relatively low level, were less than a quality standard in marine sediments, Cu, Pb, Cd, Cr, slightly higher than the average content of Guangxi inshore; gantry, Nishimura intertidal sediments Hg, Cu, Pb, Zn, Cr, As content was significantly higher than the Weizhou intertidal zone, but other elements except Cu has higher marine sediment quality level standards are not exceeded. Weizhou intertidal zone of heavy metal elements in the direction of the vertical shore distribution pattern is not obvious, human activity is relatively frequent W05, XKZ two sections near the coast direction relative enrichment; the gantry, Nishimura segment low beach heavy metal content is slightly higher than Beach and Beach, the regional distribution by different coast hydrodynamic conditions differences Qinzhou Bay sediment migration mechanism, Nishimura higher than the gantry. Weizhou intertidal zone Pb, Zn, Cr significant positive correlation in the surface sediments, Hg, Cd, As is positively related to the elements of the two groups were similar source or migration cumulative characteristics, but by the fine particle component missing 63μm the impact of them with a particle size, none of the organic carbon correlation. The gantry, Nishimura segment except the LM-02, Hg, Pb, Zn, Cr, As and particle size, organic carbon between significant positive correlation of these five elements to the natural deposition; LM-02 stations Cu , Pb, Zn anomalies account for a large proportion of the anthropogenic sources of heavy metals; study area Cu and other elements not associated with a unique provenance or deposition characteristics. When the heavy metal is the main natural source of differences in sediment dynamic environment caused by sediment grain size characteristics, thereby affecting the distribution of heavy metals, organic carbon and calcium carbonate content of different; anthropogenic sources of heavy metals accounted for a large proportion of provenance differences become The dominant factor influencing heavy metal distribution. Geological cumulative index method and potential ecological risk index method to evaluate the quality of island intertidal zone sediments found Weizhou intertidal zone sediments good quality, only Cu at individual stations mild pollution and potential ecological risk extremely low. Prevalence of Pb and Cu mild to moderately polluted partial Nishimura Island intertidal zone, the degree of risk is significantly higher than the Weizhou. The main pollution elements gantry Island intertidal zone of Cu, for mild to emphasis polluted; addition, LM-02 stations Pb and Zn partial moderately polluted, high potential ecological risk.
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